diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Update.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Update.java
index 222a25bec..8c122b071 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Update.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Update.java
@@ -314,7 +314,7 @@ public class Update {
 	 */
 	public Update multiply(String key, Number multiplier) {
 
-		Assert.notNull(multiplier, "Multiplier must not be 'null'.");
+		Assert.notNull(multiplier, "Multiplier must not be null.");
 		addMultiFieldOperation("$mul", key, multiplier.doubleValue());
 		return this;
 	}
@@ -331,7 +331,7 @@ public class Update {
 	 */
 	public Update max(String key, Object value) {
 
-		Assert.notNull(value, "Value for max operation must not be 'null'.");
+		Assert.notNull(value, "Value for max operation must not be null.");
 		addMultiFieldOperation("$max", key, value);
 		return this;
 	}
@@ -348,7 +348,7 @@ public class Update {
 	 */
 	public Update min(String key, Object value) {
 
-		Assert.notNull(value, "Value for min operation must not be 'null'.");
+		Assert.notNull(value, "Value for min operation must not be null.");
 		addMultiFieldOperation("$min", key, value);
 		return this;
 	}
@@ -780,7 +780,7 @@ public class Update {
 		 */
 		public PushOperatorBuilder sort(Direction direction) {
 
-			Assert.notNull(direction, "Direction must not be 'null'.");
+			Assert.notNull(direction, "Direction must not be null.");
 			this.modifiers.addModifier(new SortModifier(direction));
 			return this;
 		}
@@ -795,7 +795,7 @@ public class Update {
 		 */
 		public PushOperatorBuilder sort(Sort sort) {
 
-			Assert.notNull(sort, "Sort must not be 'null'.");
+			Assert.notNull(sort, "Sort must not be null.");
 			this.modifiers.addModifier(new SortModifier(sort));
 			return this;
 		}
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/UpdateMapperUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/UpdateMapperUnitTests.java
index ca13e6697..a3397bc89 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/UpdateMapperUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/UpdateMapperUnitTests.java
@@ -15,7 +15,7 @@
  */
 package org.springframework.data.mongodb.core.convert;
 
-import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 import static org.springframework.data.mongodb.core.DocumentTestUtils.*;
@@ -76,6 +76,7 @@ public class UpdateMapperUnitTests {
 	private Converter<NestedEntity, Document> writingConverterSpy;
 
 	@Before
+	@SuppressWarnings("unchecked")
 	public void setUp() {
 
 		this.writingConverterSpy = Mockito.spy(new NestedEntityWriteConverter());