diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/DurationStyle.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/DurationStyle.java
new file mode 100644
index 000000000..c7f702691
--- /dev/null
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/DurationStyle.java
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.index;
+
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import java.util.function.Function;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Duration format styles.
+ * <p/>
+ * Fork of {@code org.springframework.boot.convert.DurationStyle}.
+ *
+ * @author Phillip Webb
+ * @since 2.2
+ */
+enum DurationStyle {
+
+	/**
+	 * Simple formatting, for example '1s'.
+	 */
+	SIMPLE("^([\\+\\-]?\\d+)([a-zA-Z]{0,2})$") {
+
+		@Override
+		public Duration parse(String value, @Nullable ChronoUnit unit) {
+			try {
+				Matcher matcher = matcher(value);
+				Assert.state(matcher.matches(), "Does not match simple duration pattern");
+				String suffix = matcher.group(2);
+				return (StringUtils.hasLength(suffix) ? Unit.fromSuffix(suffix) : Unit.fromChronoUnit(unit))
+						.parse(matcher.group(1));
+			} catch (Exception ex) {
+				throw new IllegalArgumentException("'" + value + "' is not a valid simple duration", ex);
+			}
+		}
+	},
+
+	/**
+	 * ISO-8601 formatting.
+	 */
+	ISO8601("^[\\+\\-]?P.*$") {
+
+		@Override
+		public Duration parse(String value, @Nullable ChronoUnit unit) {
+			try {
+				return Duration.parse(value);
+			} catch (Exception ex) {
+				throw new IllegalArgumentException("'" + value + "' is not a valid ISO-8601 duration", ex);
+			}
+		}
+	};
+
+	private final Pattern pattern;
+
+	DurationStyle(String pattern) {
+		this.pattern = Pattern.compile(pattern);
+	}
+
+	protected final boolean matches(String value) {
+		return this.pattern.matcher(value).matches();
+	}
+
+	protected final Matcher matcher(String value) {
+		return this.pattern.matcher(value);
+	}
+
+	/**
+	 * Parse the given value to a duration.
+	 *
+	 * @param value the value to parse
+	 * @return a duration
+	 */
+	public Duration parse(String value) {
+		return parse(value, null);
+	}
+
+	/**
+	 * Parse the given value to a duration.
+	 *
+	 * @param value the value to parse
+	 * @param unit the duration unit to use if the value doesn't specify one ({@code null} will default to ms)
+	 * @return a duration
+	 */
+	public abstract Duration parse(String value, @Nullable ChronoUnit unit);
+
+	/**
+	 * Detect the style then parse the value to return a duration.
+	 *
+	 * @param value the value to parse
+	 * @return the parsed duration
+	 * @throws IllegalStateException if the value is not a known style or cannot be parsed
+	 */
+	public static Duration detectAndParse(String value) {
+		return detectAndParse(value, null);
+	}
+
+	/**
+	 * Detect the style then parse the value to return a duration.
+	 *
+	 * @param value the value to parse
+	 * @param unit the duration unit to use if the value doesn't specify one ({@code null} will default to ms)
+	 * @return the parsed duration
+	 * @throws IllegalStateException if the value is not a known style or cannot be parsed
+	 */
+	public static Duration detectAndParse(String value, @Nullable ChronoUnit unit) {
+		return detect(value).parse(value, unit);
+	}
+
+	/**
+	 * Detect the style from the given source value.
+	 *
+	 * @param value the source value
+	 * @return the duration style
+	 * @throws IllegalStateException if the value is not a known style
+	 */
+	public static DurationStyle detect(String value) {
+		Assert.notNull(value, "Value must not be null");
+		for (DurationStyle candidate : values()) {
+			if (candidate.matches(value)) {
+				return candidate;
+			}
+		}
+		throw new IllegalArgumentException("'" + value + "' is not a valid duration");
+	}
+
+	/**
+	 * Units that we support.
+	 */
+	enum Unit {
+
+		/**
+		 * Milliseconds.
+		 */
+		MILLIS(ChronoUnit.MILLIS, "ms", Duration::toMillis),
+
+		/**
+		 * Seconds.
+		 */
+		SECONDS(ChronoUnit.SECONDS, "s", Duration::getSeconds),
+
+		/**
+		 * Minutes.
+		 */
+		MINUTES(ChronoUnit.MINUTES, "m", Duration::toMinutes),
+
+		/**
+		 * Hours.
+		 */
+		HOURS(ChronoUnit.HOURS, "h", Duration::toHours),
+
+		/**
+		 * Days.
+		 */
+		DAYS(ChronoUnit.DAYS, "d", Duration::toDays);
+
+		private final ChronoUnit chronoUnit;
+
+		private final String suffix;
+
+		private Function<Duration, Long> longValue;
+
+		Unit(ChronoUnit chronoUnit, String suffix, Function<Duration, Long> toUnit) {
+			this.chronoUnit = chronoUnit;
+			this.suffix = suffix;
+			this.longValue = toUnit;
+		}
+
+		public Duration parse(String value) {
+			return Duration.of(Long.valueOf(value), this.chronoUnit);
+		}
+
+		public long longValue(Duration value) {
+			return this.longValue.apply(value);
+		}
+
+		public static Unit fromChronoUnit(ChronoUnit chronoUnit) {
+			if (chronoUnit == null) {
+				return Unit.MILLIS;
+			}
+			for (Unit candidate : values()) {
+				if (candidate.chronoUnit == chronoUnit) {
+					return candidate;
+				}
+			}
+			throw new IllegalArgumentException("Unknown unit " + chronoUnit);
+		}
+
+		public static Unit fromSuffix(String suffix) {
+			for (Unit candidate : values()) {
+				if (candidate.suffix.equalsIgnoreCase(suffix)) {
+					return candidate;
+				}
+			}
+			throw new IllegalArgumentException("Unknown unit '" + suffix + "'");
+		}
+	}
+}
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java
index 29b5756c1..5549260f6 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java
@@ -30,6 +30,7 @@ import java.lang.annotation.Target;
  * @author Thomas Darimont
  * @author Christoph Strobl
  * @author Jordi Llach
+ * @author Mark Paluch
  */
 @Target({ ElementType.ANNOTATION_TYPE, ElementType.FIELD })
 @Retention(RetentionPolicy.RUNTIME)
@@ -136,27 +137,32 @@ public @interface Indexed {
 	int expireAfterSeconds() default -1;
 
 	/**
-	 * Alternative for {@link #expireAfterSeconds()} to configure the timeout after which the collection should expire.
-	 * Defaults to an empty String for no expiry. Accepts numeric values followed by their unit of measure (d(ays),
-	 * h(ours), m(inutes), s(seconds)) or a Spring {@literal template expression}. The expression can result in a a valid
-	 * expiration {@link String} following the conventions already mentioned or a {@link java.time.Duration}.
+	 * Alternative for {@link #expireAfterSeconds()} to configure the timeout after which the document should expire.
+	 * Defaults to an empty {@link String} for no expiry. Accepts numeric values followed by their unit of measure:
+	 * <ul>
+	 * <li><b>d</b>: Days</li>
+	 * <li><b>h</b>: Hours</li>
+	 * <li><b>m</b>: Minutes</li>
+	 * <li><b>s</b>: Seconds</li>
+	 * <li>Alternatively: A Spring {@literal template expression}. The expression can result in a
+	 * {@link java.time.Duration} or a valid expiration {@link String} according to the already mentioned
+	 * conventions.</li>
+	 * </ul>
+	 * Supports ISO-8601 style.
 	 *
-	 * <pre>
-	 *     <code>
+	 * <pre class="code">
 	 *
-	 * &#0064;Indexed(expireAfter = "10s")
-	 * String expireAfterTenSeconds;
+	 * &#0064;Indexed(expireAfter = "10s") String expireAfterTenSeconds;
 	 *
-	 * &#0064;Indexed(expireAfter = "1d")
-	 * String expireAfterOneDay;
+	 * &#0064;Indexed(expireAfter = "1d") String expireAfterOneDay;
 	 *
-	 * &#0064;Indexed(expireAfter = "#{&#0064;mySpringBean.timeout}")
-	 * String expireAfterTimeoutObtainedFromSpringBean;
-	 *     </code>
+	 * &#0064;Indexed(expireAfter = "P2D") String expireAfterTwoDays;
+	 *
+	 * &#0064;Indexed(expireAfter = "#{&#0064;mySpringBean.timeout}") String expireAfterTimeoutObtainedFromSpringBean;
 	 * </pre>
 	 *
-	 * @return {@literal 0s} by default.
+	 * @return empty by default.
 	 * @since 2.2
 	 */
-	String expireAfter() default "0s";
+	String expireAfter() default "";
 }
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolver.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolver.java
index fdcdd5d2e..041241c0f 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolver.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolver.java
@@ -29,12 +29,11 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.mapping.Association;
@@ -62,7 +61,6 @@ import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
-import org.springframework.util.NumberUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
@@ -81,7 +79,6 @@ import org.springframework.util.StringUtils;
 public class MongoPersistentEntityIndexResolver implements IndexResolver {
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(MongoPersistentEntityIndexResolver.class);
-	private static final Pattern TIMEOUT_PATTERN = Pattern.compile("(\\d+)(\\W+)?([dhms])");
 	private static final SpelExpressionParser PARSER = new SpelExpressionParser();
 
 	private final MongoMappingContext mappingContext;
@@ -353,7 +350,6 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 		return indexDefinitions;
 	}
 
-	@SuppressWarnings("deprecation")
 	protected IndexDefinitionHolder createCompoundIndexDefinition(String dotPath, String collection, CompoundIndex index,
 			MongoPersistentEntity<?> entity) {
 
@@ -390,8 +386,7 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 			return new org.bson.Document(dotPath, 1);
 		}
 
-		Object keyDefToUse = evaluatePotentialTemplateExpression(keyDefinitionString,
-				getEvaluationContextForProperty(entity));
+		Object keyDefToUse = evaluate(keyDefinitionString, getEvaluationContextForProperty(entity));
 
 		org.bson.Document dbo = (keyDefToUse instanceof org.bson.Document) ? (org.bson.Document) keyDefToUse
 				: org.bson.Document.parse(ObjectUtils.nullSafeToString(keyDefToUse));
@@ -450,11 +445,11 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 			indexDefinition.expire(index.expireAfterSeconds(), TimeUnit.SECONDS);
 		}
 
-		if (!index.expireAfter().isEmpty() && !index.expireAfter().equals("0s")) {
+		if (StringUtils.hasText(index.expireAfter())) {
 
 			if (index.expireAfterSeconds() >= 0) {
 				throw new IllegalStateException(String.format(
-						"@Indexed already defines an expiration timeout of %s sec. via Indexed#expireAfterSeconds. Please make to use either expireAfterSeconds or expireAfter.",
+						"@Indexed already defines an expiration timeout of %s seconds via Indexed#expireAfterSeconds. Please make to use either expireAfterSeconds or expireAfter.",
 						index.expireAfterSeconds()));
 			}
 
@@ -480,7 +475,7 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 
 	/**
 	 * Get the {@link EvaluationContext} for a given {@link PersistentEntity entity} the default one.
-	 * 
+	 *
 	 * @param persistentEntity can be {@literal null}
 	 * @return
 	 */
@@ -546,10 +541,15 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 	private String pathAwareIndexName(String indexName, String dotPath, @Nullable PersistentEntity<?, ?> entity,
 			@Nullable MongoPersistentProperty property) {
 
-		String nameToUse = StringUtils.hasText(indexName)
-				? ObjectUtils
-						.nullSafeToString(evaluatePotentialTemplateExpression(indexName, getEvaluationContextForProperty(entity)))
-				: "";
+		String nameToUse = "";
+		if (StringUtils.hasText(indexName)) {
+
+			Object result = evaluate(indexName, getEvaluationContextForProperty(entity));
+
+			if (result != null) {
+				nameToUse = ObjectUtils.nullSafeToString(result);
+			}
+		}
 
 		if (!StringUtils.hasText(dotPath) || (property != null && dotPath.equals(property.getFieldName()))) {
 			return StringUtils.hasText(nameToUse) ? nameToUse : dotPath;
@@ -607,7 +607,7 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 	 */
 	private static Duration computeIndexTimeout(String timeoutValue, EvaluationContext evaluationContext) {
 
-		Object evaluatedTimeout = evaluatePotentialTemplateExpression(timeoutValue, evaluationContext);
+		Object evaluatedTimeout = evaluate(timeoutValue, evaluationContext);
 
 		if (evaluatedTimeout == null) {
 			return Duration.ZERO;
@@ -623,30 +623,11 @@ public class MongoPersistentEntityIndexResolver implements IndexResolver {
 			return Duration.ZERO;
 		}
 
-		Matcher matcher = TIMEOUT_PATTERN.matcher(val);
-		if (matcher.find()) {
-
-			Long timeout = NumberUtils.parseNumber(matcher.group(1), Long.class);
-			String unit = matcher.group(3);
-
-			switch (unit) {
-				case "d":
-					return Duration.ofDays(timeout);
-				case "h":
-					return Duration.ofHours(timeout);
-				case "m":
-					return Duration.ofMinutes(timeout);
-				case "s":
-					return Duration.ofSeconds(timeout);
-			}
-		}
-
-		throw new IllegalArgumentException(
-				String.format("Index timeout %s cannot be parsed. Please use the following pattern '\\d+\\W?[dhms]'.", val));
+		return DurationStyle.detectAndParse(val);
 	}
 
 	@Nullable
-	private static Object evaluatePotentialTemplateExpression(String value, EvaluationContext evaluationContext) {
+	private static Object evaluate(String value, EvaluationContext evaluationContext) {
 
 		Expression expression = PARSER.parseExpression(value, ParserContext.TEMPLATE_EXPRESSION);
 		if (expression instanceof LiteralExpression) {
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/IndexingIntegrationTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/IndexingIntegrationTests.java
index 76fc212f9..e2c8fe522 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/IndexingIntegrationTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/IndexingIntegrationTests.java
@@ -15,8 +15,7 @@
  */
 package org.springframework.data.mongodb.core.index;
 
-import static org.hamcrest.CoreMatchers.*;
-import static org.junit.Assert.*;
+import static org.springframework.data.mongodb.test.util.Assertions.*;
 
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
@@ -32,6 +31,7 @@ import java.util.Optional;
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -46,7 +46,6 @@ import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
 import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
-import org.springframework.data.mongodb.test.util.Assertions;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@@ -99,7 +98,7 @@ public class IndexingIntegrationTests {
 
 		operations.getConverter().getMappingContext().getPersistentEntity(IndexedPerson.class);
 
-		assertThat(hasIndex("_firstname", IndexedPerson.class), is(true));
+		assertThat(hasIndex("_firstname", IndexedPerson.class)).isTrue();
 	}
 
 	@Test // DATAMONGO-2188
@@ -114,7 +113,7 @@ public class IndexingIntegrationTests {
 
 		template.getConverter().getMappingContext().getPersistentEntity(IndexedPerson.class);
 
-		assertThat(hasIndex("_firstname", MongoCollectionUtils.getPreferredCollectionName(IndexedPerson.class)), is(false));
+		assertThat(hasIndex("_firstname", MongoCollectionUtils.getPreferredCollectionName(IndexedPerson.class))).isFalse();
 	}
 
 	@Test // DATAMONGO-1163
@@ -123,7 +122,7 @@ public class IndexingIntegrationTests {
 
 		operations.getConverter().getMappingContext().getPersistentEntity(IndexedPerson.class);
 
-		assertThat(hasIndex("_lastname", IndexedPerson.class), is(true));
+		assertThat(hasIndex("_lastname", IndexedPerson.class)).isTrue();
 	}
 
 	@Test // DATAMONGO-2112
@@ -140,8 +139,8 @@ public class IndexingIntegrationTests {
 					.findFirst();
 		});
 
-		Assertions.assertThat(indexInfo).isPresent();
-		Assertions.assertThat(indexInfo.get()).containsEntry("expireAfterSeconds", 11L);
+		assertThat(indexInfo).isPresent();
+		assertThat(indexInfo.get()).containsEntry("expireAfterSeconds", 11L);
 	}
 
 	@Target({ ElementType.FIELD })
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java
index 1b35616c0..7bac84fe0 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java
@@ -15,10 +15,8 @@
  */
 package org.springframework.data.mongodb.core.index;
 
-import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
-import static org.springframework.data.mongodb.test.util.IsBsonObject.*;
+import static org.springframework.data.mongodb.test.util.Assertions.*;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
@@ -27,11 +25,11 @@ import java.lang.annotation.Target;
 import java.util.Collections;
 import java.util.List;
 
-import org.assertj.core.api.Assertions;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Suite;
 import org.junit.runners.Suite.SuiteClasses;
+
 import org.springframework.core.annotation.AliasFor;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.geo.Point;
@@ -53,12 +51,15 @@ import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.util.ClassTypeInformation;
 
 /**
+ * Tests for {@link MongoPersistentEntityIndexResolver}.
+ *
  * @author Christoph Strobl
  * @author Mark Paluch
  */
 @RunWith(Suite.class)
 @SuiteClasses({ IndexResolutionTests.class, GeoSpatialIndexResolutionTests.class, CompoundIndexResolutionTests.class,
 		TextIndexedResolutionTests.class, MixedIndexResolutionTests.class })
+@SuppressWarnings("unused")
 public class MongoPersistentEntityIndexResolverUnitTests {
 
 	/**
@@ -75,7 +76,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					IndexOnLevelZero.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("indexedProperty", "Zero", indexDefinitions.get(0));
 		}
 
@@ -84,7 +85,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(IndexOnLevelOne.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("zero.indexedProperty", "One", indexDefinitions.get(0));
 		}
 
@@ -95,7 +96,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			IndexResolver indexResolver = IndexResolver.create(mappingContext);
 			Iterable<? extends IndexDefinition> definitions = indexResolver.resolveIndexFor(IndexOnLevelOne.class);
 
-			assertThat(definitions.iterator().hasNext(), is(true));
+			assertThat(definitions).isNotEmpty();
 		}
 
 		@Test // DATAMONGO-899
@@ -103,7 +104,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(IndexOnLevelTwo.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("one.zero.indexedProperty", "Two", indexDefinitions.get(0));
 		}
 
@@ -113,7 +114,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					IndexOnLevelOneWithExplicitlyNamedField.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("customZero.customFieldName", "indexOnLevelOneWithExplicitlyNamedField",
 					indexDefinitions.get(0));
 		}
@@ -125,7 +126,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 					IndexOnLevelZero.class);
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
-			assertThat(indexDefinition.getIndexOptions(), equalTo(new org.bson.Document().append("name", "indexedProperty")));
+			assertThat(indexDefinition.getIndexOptions()).isEqualTo(new org.bson.Document("name", "indexedProperty"));
 		}
 
 		@Test // DATAMONGO-899
@@ -135,8 +136,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 					WithOptionsOnIndexedProperty.class);
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
-			assertThat(indexDefinition.getIndexOptions(), equalTo(new org.bson.Document().append("name", "indexedProperty")
-					.append("unique", true).append("sparse", true).append("background", true).append("expireAfterSeconds", 10L)));
+			assertThat(indexDefinition.getIndexOptions()).isEqualTo(new org.bson.Document().append("name", "indexedProperty")
+					.append("unique", true).append("sparse", true).append("background", true).append("expireAfterSeconds", 10L));
 		}
 
 		@Test // DATAMONGO-1297
@@ -144,9 +145,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(WithDbRef.class);
 
-			assertThat(indexDefinitions, hasSize(1));
-			assertThat(indexDefinitions.get(0).getCollection(), equalTo("withDbRef"));
-			assertThat(indexDefinitions.get(0).getIndexKeys(), equalTo(new org.bson.Document().append("indexedDbRef", 1)));
+			assertThat(indexDefinitions).hasSize(1);
+			assertThat(indexDefinitions.get(0).getCollection()).isEqualTo("withDbRef");
+			assertThat(indexDefinitions.get(0).getIndexKeys()).isEqualTo(new org.bson.Document("indexedDbRef", 1));
 		}
 
 		@Test // DATAMONGO-1297
@@ -155,10 +156,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					WrapperOfWithDbRef.class);
 
-			assertThat(indexDefinitions, hasSize(1));
-			assertThat(indexDefinitions.get(0).getCollection(), equalTo("wrapperOfWithDbRef"));
-			assertThat(indexDefinitions.get(0).getIndexKeys(),
-					equalTo(new org.bson.Document().append("nested.indexedDbRef", 1)));
+			assertThat(indexDefinitions).hasSize(1);
+			assertThat(indexDefinitions.get(0).getCollection()).isEqualTo("wrapperOfWithDbRef");
+			assertThat(indexDefinitions.get(0).getIndexKeys()).isEqualTo(new org.bson.Document("nested.indexedDbRef", 1));
 		}
 
 		@Test // DATAMONGO-1163
@@ -167,9 +167,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					IndexOnMetaAnnotatedField.class);
 
-			assertThat(indexDefinitions, hasSize(1));
-			assertThat(indexDefinitions.get(0).getCollection(), equalTo("indexOnMetaAnnotatedField"));
-			assertThat(indexDefinitions.get(0).getIndexOptions(), equalTo(new org.bson.Document().append("name", "_name")));
+			assertThat(indexDefinitions).hasSize(1);
+			assertThat(indexDefinitions.get(0).getCollection()).isEqualTo("indexOnMetaAnnotatedField");
+			assertThat(indexDefinitions.get(0).getIndexOptions()).isEqualTo(new org.bson.Document("name", "_name"));
 		}
 
 		@Test // DATAMONGO-1373
@@ -178,13 +178,15 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					IndexedDocumentWithComposedAnnotations.class);
 
-			assertThat(indexDefinitions, hasSize(2));
+			assertThat(indexDefinitions).hasSize(2);
 
 			IndexDefinitionHolder indexDefinitionHolder = indexDefinitions.get(1);
 
-			assertThat(indexDefinitionHolder.getIndexKeys(), isBsonObject().containing("fieldWithMyIndexName", 1));
-			assertThat(indexDefinitionHolder.getIndexOptions(),
-					isBsonObject().containing("sparse", true).containing("unique", true).containing("name", "my_index_name"));
+			assertThat(indexDefinitionHolder.getIndexKeys()).containsEntry("fieldWithMyIndexName", 1);
+			assertThat(indexDefinitionHolder.getIndexOptions()) //
+					.containsEntry("sparse", true) //
+					.containsEntry("unique", true) //
+					.containsEntry("name", "my_index_name");
 		}
 
 		@Test // DATAMONGO-1373
@@ -193,13 +195,15 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					IndexedDocumentWithComposedAnnotations.class);
 
-			assertThat(indexDefinitions, hasSize(2));
+			assertThat(indexDefinitions).hasSize(2);
 
 			IndexDefinitionHolder indexDefinitionHolder = indexDefinitions.get(0);
 
-			assertThat(indexDefinitionHolder.getIndexKeys(), isBsonObject().containing("fieldWithDifferentIndexName", 1));
-			assertThat(indexDefinitionHolder.getIndexOptions(),
-					isBsonObject().containing("sparse", true).containing("name", "different_name").notContaining("unique"));
+			assertThat(indexDefinitionHolder.getIndexKeys()).containsEntry("fieldWithDifferentIndexName", 1);
+			assertThat(indexDefinitionHolder.getIndexOptions()) //
+					.containsEntry("sparse", true) //
+					.containsEntry("name", "different_name") //
+					.doesNotContainKey("unique");
 		}
 
 		@Test // DATAMONGO-2112
@@ -208,7 +212,16 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					WithExpireAfterAsPlainString.class);
 
-			Assertions.assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 600L);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 600L);
+		}
+
+		@Test // DATAMONGO-2112
+		public void shouldResolveTimeoutFromIso8601String() {
+
+			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
+					WithIso8601Style.class);
+
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 86400L);
 		}
 
 		@Test // DATAMONGO-2112
@@ -217,7 +230,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					WithExpireAfterAsExpression.class);
 
-			Assertions.assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 11L);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 11L);
 		}
 
 		@Test // DATAMONGO-2112
@@ -226,7 +239,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					WithExpireAfterAsExpressionResultingInDuration.class);
 
-			Assertions.assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 100L);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("expireAfterSeconds", 100L);
 		}
 
 		@Test // DATAMONGO-2112
@@ -235,9 +248,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			MongoMappingContext mappingContext = prepareMappingContext(WithInvalidExpireAfter.class);
 			MongoPersistentEntityIndexResolver indexResolver = new MongoPersistentEntityIndexResolver(mappingContext);
 
-			Assertions.assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> indexResolver
+			assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> indexResolver
 					.resolveIndexForEntity(mappingContext.getRequiredPersistentEntity(WithInvalidExpireAfter.class)));
-
 		}
 
 		@Test // DATAMONGO-2112
@@ -246,7 +258,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			MongoMappingContext mappingContext = prepareMappingContext(WithDuplicateExpiry.class);
 			MongoPersistentEntityIndexResolver indexResolver = new MongoPersistentEntityIndexResolver(mappingContext);
 
-			Assertions.assertThatExceptionOfType(IllegalStateException.class).isThrownBy(() -> indexResolver
+			assertThatExceptionOfType(IllegalStateException.class).isThrownBy(() -> indexResolver
 					.resolveIndexForEntity(mappingContext.getRequiredPersistentEntity(WithDuplicateExpiry.class)));
 		}
 
@@ -256,7 +268,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					WithIndexNameAsExpression.class);
 
-			Assertions.assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "my1st");
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "my1st");
 		}
 
 		@Document("Zero")
@@ -322,13 +334,13 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 		@Retention(RetentionPolicy.RUNTIME)
 		@Target({ ElementType.FIELD })
 		@ComposedIndexedAnnotation(indexName = "different_name", beUnique = false)
-		static @interface CustomIndexedAnnotation {
+		@interface CustomIndexedAnnotation {
 		}
 
 		@Retention(RetentionPolicy.RUNTIME)
 		@Target({ ElementType.FIELD, ElementType.ANNOTATION_TYPE })
 		@Indexed
-		static @interface ComposedIndexedAnnotation {
+		@interface ComposedIndexedAnnotation {
 
 			@AliasFor(annotation = Indexed.class, attribute = "unique")
 			boolean beUnique() default true;
@@ -343,7 +355,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 		@Retention(RetentionPolicy.RUNTIME)
 		@Target(ElementType.FIELD)
 		@org.springframework.data.mongodb.core.mapping.Field
-		static @interface ComposedFieldAnnotation {
+		@interface ComposedFieldAnnotation {
 
 			@AliasFor(annotation = org.springframework.data.mongodb.core.mapping.Field.class, attribute = "value")
 			String name() default "_id";
@@ -354,6 +366,11 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			@Indexed(expireAfter = "10m") String withTimeout;
 		}
 
+		@Document
+		class WithIso8601Style {
+			@Indexed(expireAfter = "P1D") String withTimeout;
+		}
+
 		@Document
 		static class WithExpireAfterAsExpression {
 			@Indexed(expireAfter = "#{10 + 1 + 's'}") String withTimeout;
@@ -384,7 +401,6 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 	@Retention(RetentionPolicy.RUNTIME)
 	@Indexed
 	@interface IndexedFieldAnnotation {
-
 	}
 
 	@Document
@@ -405,7 +421,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					GeoSpatialIndexOnLevelZero.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("geoIndexedProperty", "Zero", indexDefinitions.get(0));
 		}
 
@@ -415,7 +431,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					GeoSpatialIndexOnLevelOne.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("zero.geoIndexedProperty", "One", indexDefinitions.get(0));
 		}
 
@@ -425,7 +441,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					GeoSpatialIndexOnLevelTwo.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("one.zero.geoIndexedProperty", "Two", indexDefinitions.get(0));
 		}
 
@@ -437,8 +453,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
 
-			assertThat(indexDefinition.getIndexOptions(), equalTo(
-					new org.bson.Document().append("name", "location").append("min", 1).append("max", 100).append("bits", 2)));
+			assertThat(indexDefinition.getIndexOptions()).isEqualTo(
+					new org.bson.Document().append("name", "location").append("min", 1).append("max", 100).append("bits", 2));
 		}
 
 		@Test // DATAMONGO-1373
@@ -449,10 +465,10 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
 
-			assertThat(indexDefinition.getIndexKeys(),
-					isBsonObject().containing("location", "geoHaystack").containing("What light?", 1));
-			assertThat(indexDefinition.getIndexOptions(),
-					isBsonObject().containing("name", "my_geo_index_name").containing("bucketSize", 2.0));
+			assertThat(indexDefinition.getIndexKeys()).containsEntry("location", "geoHaystack").containsEntry("What light?",
+					1);
+			assertThat(indexDefinition.getIndexOptions()).containsEntry("name", "my_geo_index_name")
+					.containsEntry("bucketSize", 2.0);
 		}
 
 		@Test // DATAMONGO-2112
@@ -461,7 +477,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					GeoIndexWithNameAsExpression.class);
 
-			Assertions.assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "my1st");
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "my1st");
 		}
 
 		@Document("Zero")
@@ -531,7 +547,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CompoundIndexOnLevelZero.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "foo", "bar" }, "CompoundIndexOnLevelZero", indexDefinitions.get(0));
 		}
 
@@ -542,9 +558,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 					CompoundIndexOnLevelZero.class);
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
-			assertThat(indexDefinition.getIndexOptions(), equalTo(new org.bson.Document().append("name", "compound_index")
-					.append("unique", true).append("sparse", true).append("background", true)));
-			assertThat(indexDefinition.getIndexKeys(), equalTo(new org.bson.Document().append("foo", 1).append("bar", -1)));
+			assertThat(indexDefinition.getIndexOptions()).isEqualTo(new org.bson.Document("name", "compound_index")
+					.append("unique", true).append("sparse", true).append("background", true));
+			assertThat(indexDefinition.getIndexKeys()).isEqualTo(new org.bson.Document().append("foo", 1).append("bar", -1));
 		}
 
 		@Test // DATAMONGO-909
@@ -554,9 +570,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 					IndexDefinedOnSuperClass.class);
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
-			assertThat(indexDefinition.getIndexOptions(), equalTo(new org.bson.Document().append("name", "compound_index")
-					.append("unique", true).append("sparse", true).append("background", true)));
-			assertThat(indexDefinition.getIndexKeys(), equalTo(new org.bson.Document().append("foo", 1).append("bar", -1)));
+			assertThat(indexDefinition.getIndexOptions()).isEqualTo(new org.bson.Document().append("name", "compound_index")
+					.append("unique", true).append("sparse", true).append("background", true));
+			assertThat(indexDefinition.getIndexKeys()).isEqualTo(new org.bson.Document().append("foo", 1).append("bar", -1));
 		}
 
 		@Test // DATAMONGO-827
@@ -566,9 +582,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 					ComountIndexWithAutogeneratedName.class);
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
-			assertThat(indexDefinition.getIndexOptions(),
-					equalTo(new org.bson.Document().append("unique", true).append("sparse", true).append("background", true)));
-			assertThat(indexDefinition.getIndexKeys(), equalTo(new org.bson.Document().append("foo", 1).append("bar", -1)));
+			assertThat(indexDefinition.getIndexOptions())
+					.isEqualTo(new org.bson.Document().append("unique", true).append("sparse", true).append("background", true));
+			assertThat(indexDefinition.getIndexKeys()).isEqualTo(new org.bson.Document().append("foo", 1).append("bar", -1));
 		}
 
 		@Test // DATAMONGO-929
@@ -577,7 +593,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CompoundIndexOnLevelOne.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "zero.foo", "zero.bar" }, "CompoundIndexOnLevelOne",
 					indexDefinitions.get(0));
 		}
@@ -588,7 +604,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CompoundIndexOnLevelOneWithEmptyIndexDefinition.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "zero" }, "CompoundIndexOnLevelZeroWithEmptyIndexDef",
 					indexDefinitions.get(0));
 		}
@@ -599,7 +615,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					SingleCompoundIndex.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "foo", "bar" }, "CompoundIndexOnLevelZero", indexDefinitions.get(0));
 		}
 
@@ -609,10 +625,10 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CompoundIndexDocumentWithComposedAnnotation.class);
 
-			assertThat(indexDefinitions, hasSize(1));
-			assertThat(indexDefinitions.get(0).getIndexKeys(), isBsonObject().containing("foo", 1).containing("bar", -1));
-			assertThat(indexDefinitions.get(0).getIndexOptions(), isBsonObject().containing("name", "my_compound_index_name")
-					.containing("unique", true).containing("background", true));
+			assertThat(indexDefinitions).hasSize(1);
+			assertThat(indexDefinitions.get(0).getIndexKeys()).containsEntry("foo", 1).containsEntry("bar", -1);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "my_compound_index_name")
+					.containsEntry("unique", true).containsEntry("background", true);
 		}
 
 		@Test // DATAMONGO-2112
@@ -621,7 +637,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CompoundIndexWithNameExpression.class);
 
-			Assertions.assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "cmp2name");
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "cmp2name");
 		}
 
 		@Test // DATAMONGO-2112
@@ -630,7 +646,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CompoundIndexWithDefExpression.class);
 
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "foo", "bar" }, "compoundIndexWithDefExpression",
 					indexDefinitions.get(0));
 		}
@@ -660,22 +676,16 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 				unique = true)
 		static class SingleCompoundIndex {}
 
-		static class IndexDefinedOnSuperClass extends CompoundIndexOnLevelZero {
-
-		}
+		static class IndexDefinedOnSuperClass extends CompoundIndexOnLevelZero {}
 
 		@Document("ComountIndexWithAutogeneratedName")
 		@CompoundIndexes({ @CompoundIndex(useGeneratedName = true, def = "{'foo': 1, 'bar': -1}", background = true,
 				sparse = true, unique = true) })
-		static class ComountIndexWithAutogeneratedName {
-
-		}
+		static class ComountIndexWithAutogeneratedName {}
 
 		@Document("WithComposedAnnotation")
 		@ComposedCompoundIndex
-		static class CompoundIndexDocumentWithComposedAnnotation {
-
-		}
+		static class CompoundIndexDocumentWithComposedAnnotation {}
 
 		@Retention(RetentionPolicy.RUNTIME)
 		@Target({ ElementType.TYPE })
@@ -716,7 +726,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					TextIndexOnSinglePropertyInRoot.class);
-			assertThat(indexDefinitions.size(), equalTo(1));
+
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection("bar", "textIndexOnSinglePropertyInRoot", indexDefinitions.get(0));
 		}
 
@@ -725,7 +736,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					TextIndexOnMutiplePropertiesInRoot.class);
-			assertThat(indexDefinitions.size(), equalTo(1));
+
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "foo", "bar" }, "textIndexOnMutiplePropertiesInRoot",
 					indexDefinitions.get(0));
 		}
@@ -735,7 +747,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					TextIndexOnNestedRoot.class);
-			assertThat(indexDefinitions.size(), equalTo(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "nested.foo" }, "textIndexOnNestedRoot", indexDefinitions.get(0));
 		}
 
@@ -744,12 +756,12 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					TextIndexOnNestedWithWeightRoot.class);
-			assertThat(indexDefinitions.size(), equalTo(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "nested.foo" }, "textIndexOnNestedWithWeightRoot",
 					indexDefinitions.get(0));
 
 			org.bson.Document weights = DocumentTestUtils.getAsDocument(indexDefinitions.get(0).getIndexOptions(), "weights");
-			assertThat(weights.get("nested.foo"), is((Object) 5F));
+			assertThat(weights.get("nested.foo")).isEqualTo(5F);
 		}
 
 		@Test // DATAMONGO-937
@@ -757,13 +769,13 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					TextIndexOnNestedWithMostSpecificValueRoot.class);
-			assertThat(indexDefinitions.size(), equalTo(1));
+			assertThat(indexDefinitions).hasSize(1);
 			assertIndexPathAndCollection(new String[] { "nested.foo", "nested.bar" },
 					"textIndexOnNestedWithMostSpecificValueRoot", indexDefinitions.get(0));
 
 			org.bson.Document weights = DocumentTestUtils.getAsDocument(indexDefinitions.get(0).getIndexOptions(), "weights");
-			assertThat(weights.get("nested.foo"), is((Object) 5F));
-			assertThat(weights.get("nested.bar"), is((Object) 10F));
+			assertThat(weights.get("nested.foo")).isEqualTo(5F);
+			assertThat(weights.get("nested.bar")).isEqualTo(10F);
 		}
 
 		@Test // DATAMONGO-937
@@ -771,7 +783,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithDefaultLanguage.class);
-			assertThat(indexDefinitions.get(0).getIndexOptions().get("default_language"), is((Object) "spanish"));
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("default_language", "spanish");
 		}
 
 		@Test // DATAMONGO-937, DATAMONGO-1049
@@ -779,7 +791,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithLanguageOverride.class);
-			assertThat(indexDefinitions.get(0).getIndexOptions().get("language_override"), is((Object) "lang"));
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("language_override", "lang");
 		}
 
 		@Test // DATAMONGO-1049
@@ -787,7 +799,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithLanguageOverrideOnNestedElement.class);
-			assertThat(indexDefinitions.get(0).getIndexOptions().get("language_override"), is(nullValue()));
+			assertThat(indexDefinitions.get(0).getIndexOptions().get("language_override")).isNull();
 		}
 
 		@Test // DATAMONGO-1049
@@ -795,7 +807,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNoTextIndexPropertyButReservedFieldLanguage.class);
-			assertThat(indexDefinitions, is(empty()));
+
+			assertThat(indexDefinitions).isEmpty();
 		}
 
 		@Test // DATAMONGO-1049
@@ -803,7 +816,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNoTextIndexPropertyButReservedFieldLanguageAnnotated.class);
-			assertThat(indexDefinitions, is(empty()));
+
+			assertThat(indexDefinitions).isEmpty();
 		}
 
 		@Test // DATAMONGO-1049
@@ -811,7 +825,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithOverlappingLanguageProps.class);
-			assertThat(indexDefinitions.get(0).getIndexOptions().get("language_override"), is((Object) "lang"));
+
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("language_override", "lang");
 		}
 
 		@Test // DATAMONGO-1373
@@ -821,7 +836,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 					TextIndexedDocumentWithComposedAnnotation.class);
 
 			org.bson.Document weights = DocumentTestUtils.getAsDocument(indexDefinitions.get(0).getIndexOptions(), "weights");
-			assertThat(weights, isBsonObject().containing("foo", 99f));
+			assertThat(weights).containsEntry("foo", 99f);
 		}
 
 		@Document
@@ -919,7 +934,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 		@Retention(RetentionPolicy.RUNTIME)
 		@Target({ ElementType.FIELD, ElementType.ANNOTATION_TYPE })
 		@TextIndexed
-		static @interface ComposedTextIndexedAnnotation {
+		@interface ComposedTextIndexedAnnotation {
 
 			@AliasFor(annotation = TextIndexed.class, attribute = "weight")
 			float heavyweight() default 99f;
@@ -933,25 +948,27 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(MixedIndexRoot.class);
 
-			assertThat(indexDefinitions, hasSize(2));
-			assertThat(indexDefinitions.get(0).getIndexDefinition(), instanceOf(Index.class));
-			assertThat(indexDefinitions.get(1).getIndexDefinition(), instanceOf(GeospatialIndex.class));
+			assertThat(indexDefinitions).hasSize(2);
+			assertThat(indexDefinitions.get(0).getIndexDefinition()).isInstanceOf(Index.class);
+			assertThat(indexDefinitions.get(1).getIndexDefinition()).isInstanceOf(GeospatialIndex.class);
 		}
 
 		@Test // DATAMONGO-899
 		public void cyclicPropertyReferenceOverDBRefShouldNotBeTraversed() {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(Inner.class);
-			assertThat(indexDefinitions, hasSize(1));
-			assertThat(indexDefinitions.get(0).getIndexDefinition().getIndexKeys(),
-					equalTo(new org.bson.Document().append("outer", 1)));
+
+			assertThat(indexDefinitions).hasSize(1);
+			assertThat(indexDefinitions.get(0).getIndexDefinition().getIndexKeys())
+					.isEqualTo(new org.bson.Document().append("outer", 1));
 		}
 
 		@Test // DATAMONGO-899
 		public void associationsShouldNotBeTraversed() {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(Outer.class);
-			assertThat(indexDefinitions, empty());
+
+			assertThat(indexDefinitions).isEmpty();
 		}
 
 		@Test // DATAMONGO-926
@@ -959,7 +976,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					CycleStartingInBetween.class);
-			assertThat(indexDefinitions, hasSize(1));
+
+			assertThat(indexDefinitions).hasSize(1);
 		}
 
 		@Test // DATAMONGO-926
@@ -968,7 +986,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(CycleLevelZero.class);
 			assertIndexPathAndCollection("indexedProperty", "cycleLevelZero", indexDefinitions.get(0));
 			assertIndexPathAndCollection("cyclicReference.indexedProperty", "cycleLevelZero", indexDefinitions.get(1));
-			assertThat(indexDefinitions, hasSize(2));
+			assertThat(indexDefinitions).hasSize(2);
 		}
 
 		@Test // DATAMONGO-926
@@ -976,7 +994,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(CycleOnLevelOne.class);
 			assertIndexPathAndCollection("reference.indexedProperty", "cycleOnLevelOne", indexDefinitions.get(0));
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 		}
 
 		@Test // DATAMONGO-926
@@ -984,11 +1002,12 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					NoCycleButIdenticallyNamedProperties.class);
+
+			assertThat(indexDefinitions).hasSize(3);
 			assertIndexPathAndCollection("foo", "noCycleButIdenticallyNamedProperties", indexDefinitions.get(0));
 			assertIndexPathAndCollection("reference.foo", "noCycleButIdenticallyNamedProperties", indexDefinitions.get(1));
 			assertIndexPathAndCollection("reference.deep.foo", "noCycleButIdenticallyNamedProperties",
 					indexDefinitions.get(2));
-			assertThat(indexDefinitions, hasSize(3));
 		}
 
 		@Test // DATAMONGO-949
@@ -997,7 +1016,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					SimilarityHolingBean.class);
 			assertIndexPathAndCollection("norm", "similarityHolingBean", indexDefinitions.get(0));
-			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions).hasSize(1);
 		}
 
 		@Test // DATAMONGO-962
@@ -1005,7 +1024,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					SelfCyclingViaCollectionType.class);
-			assertThat(indexDefinitions, empty());
+
+			assertThat(indexDefinitions).isEmpty();
 		}
 
 		@Test // DATAMONGO-962
@@ -1013,14 +1033,15 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					MultipleObjectsOfSameType.class);
-			assertThat(indexDefinitions, empty());
+
+			assertThat(indexDefinitions).isEmpty();
 		}
 
 		@Test // DATAMONGO-962
 		@SuppressWarnings({ "rawtypes", "unchecked" })
 		public void shouldCatchCyclicReferenceExceptionOnRoot() {
 
-			MongoPersistentEntity entity = new BasicMongoPersistentEntity<Object>(ClassTypeInformation.from(Object.class));
+			MongoPersistentEntity entity = new BasicMongoPersistentEntity<>(ClassTypeInformation.from(Object.class));
 
 			MongoPersistentProperty propertyMock = mock(MongoPersistentProperty.class);
 			when(propertyMock.isEntity()).thenReturn(true);
@@ -1028,7 +1049,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			when(propertyMock.getActualType()).thenThrow(
 					new MongoPersistentEntityIndexResolver.CyclicPropertyReferenceException("foo", Object.class, "bar"));
 
-			MongoPersistentEntity<SelfCyclingViaCollectionType> selfCyclingEntity = new BasicMongoPersistentEntity<SelfCyclingViaCollectionType>(
+			MongoPersistentEntity<SelfCyclingViaCollectionType> selfCyclingEntity = new BasicMongoPersistentEntity<>(
 					ClassTypeInformation.from(SelfCyclingViaCollectionType.class));
 
 			new MongoPersistentEntityIndexResolver(prepareMappingContext(SelfCyclingViaCollectionType.class))
@@ -1041,9 +1062,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					NoCycleManyPathsToDeepValueObject.class);
 
+			assertThat(indexDefinitions).hasSize(2);
 			assertIndexPathAndCollection("l3.valueObject.value", "rules", indexDefinitions.get(0));
 			assertIndexPathAndCollection("l2.l3.valueObject.value", "rules", indexDefinitions.get(1));
-			assertThat(indexDefinitions, hasSize(2));
 		}
 
 		@Test // DATAMONGO-1025
@@ -1051,8 +1072,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNestedDocumentHavingNamedCompoundIndex.class);
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"),
-					equalTo("propertyOfTypeHavingNamedCompoundIndex.c_index"));
+
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name",
+					"propertyOfTypeHavingNamedCompoundIndex.c_index");
 		}
 
 		@Test // DATAMONGO-1025
@@ -1060,8 +1082,8 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNestedTypeHavingNamedCompoundIndex.class);
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"),
-					equalTo("propertyOfTypeHavingNamedCompoundIndex.c_index"));
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name",
+					"propertyOfTypeHavingNamedCompoundIndex.c_index");
 		}
 
 		@Test // DATAMONGO-1025
@@ -1069,8 +1091,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNestedDocumentHavingNamedIndex.class);
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"),
-					equalTo("propertyOfTypeHavingNamedIndex.property_index"));
+
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name",
+					"propertyOfTypeHavingNamedIndex.property_index");
 		}
 
 		@Test // DATAMONGO-1025
@@ -1078,8 +1101,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNestedTypeHavingNamedIndex.class);
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"),
-					equalTo("propertyOfTypeHavingNamedIndex.property_index"));
+
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name",
+					"propertyOfTypeHavingNamedIndex.property_index");
 		}
 
 		@Test // DATAMONGO-1025
@@ -1087,7 +1111,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					DocumentWithNamedIndex.class);
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"), equalTo("property_index"));
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "property_index");
 		}
 
 		@Test // DATAMONGO-1087
@@ -1096,9 +1120,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					MultiplePropertiesOfSameTypeWithMatchingStartLetters.class);
 
-			assertThat(indexDefinitions, hasSize(2));
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"), equalTo("name.component"));
-			assertThat((String) indexDefinitions.get(1).getIndexOptions().get("name"), equalTo("nameLast.component"));
+			assertThat(indexDefinitions).hasSize(2);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "name.component");
+			assertThat(indexDefinitions.get(1).getIndexOptions()).containsEntry("name", "nameLast.component");
 		}
 
 		@Test // DATAMONGO-1087
@@ -1107,9 +1131,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					MultiplePropertiesOfSameTypeWithMatchingStartLettersOnNestedProperty.class);
 
-			assertThat(indexDefinitions, hasSize(2));
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"), equalTo("component.nameLast"));
-			assertThat((String) indexDefinitions.get(1).getIndexOptions().get("name"), equalTo("component.name"));
+			assertThat(indexDefinitions).hasSize(2);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "component.nameLast");
+			assertThat(indexDefinitions.get(1).getIndexOptions()).containsEntry("name", "component.name");
 		}
 
 		@Test // DATAMONGO-1121
@@ -1118,11 +1142,10 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					OuterDocumentReferingToIndexedPropertyViaDifferentNonCyclingPaths.class);
 
-			assertThat(indexDefinitions, hasSize(2));
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"), equalTo("path1.foo"));
-			assertThat((String) indexDefinitions.get(1).getIndexOptions().get("name"),
-					equalTo("path2.propertyWithIndexedStructure.foo"));
-
+			assertThat(indexDefinitions).hasSize(2);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name", "path1.foo");
+			assertThat(indexDefinitions.get(1).getIndexOptions()).containsEntry("name",
+					"path2.propertyWithIndexedStructure.foo");
 		}
 
 		@Test // DATAMONGO-1263
@@ -1131,9 +1154,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
 					EntityWithGenericTypeWrapperAsElement.class);
 
-			assertThat(indexDefinitions, hasSize(1));
-			assertThat((String) indexDefinitions.get(0).getIndexOptions().get("name"),
-					equalTo("listWithGeneircTypeElement.entity.property_index"));
+			assertThat(indexDefinitions).hasSize(1);
+			assertThat(indexDefinitions.get(0).getIndexOptions()).containsEntry("name",
+					"listWithGeneircTypeElement.entity.property_index");
 		}
 
 		@Document
@@ -1365,9 +1388,9 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 			IndexDefinitionHolder holder) {
 
 		for (String expectedPath : expectedPaths) {
-			assertThat(holder.getIndexDefinition().getIndexKeys().containsKey(expectedPath), equalTo(true));
+			assertThat(holder.getIndexDefinition().getIndexKeys()).containsKey(expectedPath);
 		}
 
-		assertThat(holder.getCollection(), equalTo(expectedCollection));
+		assertThat(holder.getCollection()).isEqualTo(expectedCollection);
 	}
 }
diff --git a/src/main/asciidoc/new-features.adoc b/src/main/asciidoc/new-features.adoc
index 56d296206..a7098caa8 100644
--- a/src/main/asciidoc/new-features.adoc
+++ b/src/main/asciidoc/new-features.adoc
@@ -14,6 +14,7 @@
 * Kotlin extension methods accepting `KClass` are deprecated now in favor of `reified` methods.
 * Support of array filters in `Update` operations.
 * <<mongo.jsonSchema.generated, JSON Schema generation>> from domain types.
+* SpEL support in for expressions in `@Indexed`.
 
 [[new-features.2-1-0]]
 == What's New in Spring Data MongoDB 2.1