diff --git a/src/main/java/org/springframework/data/keyvalue/repository/support/QuerydslKeyValueRepository.java b/src/main/java/org/springframework/data/keyvalue/repository/support/QuerydslKeyValueRepository.java
index 35c2ed8..99cec6f 100644
--- a/src/main/java/org/springframework/data/keyvalue/repository/support/QuerydslKeyValueRepository.java
+++ b/src/main/java/org/springframework/data/keyvalue/repository/support/QuerydslKeyValueRepository.java
@@ -15,10 +15,12 @@
  */
 package org.springframework.data.keyvalue.repository.support;
 
-import static org.springframework.data.keyvalue.repository.support.KeyValueQuerydslUtils.toOrderSpecifier;
+import static org.springframework.data.keyvalue.repository.support.KeyValueQuerydslUtils.*;
 
 import java.io.Serializable;
+import java.util.Optional;
 
+import org.springframework.dao.IncorrectResultSizeDataAccessException;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
@@ -34,6 +36,7 @@ import org.springframework.util.ObjectUtils;
 
 import com.querydsl.collections.AbstractCollQuery;
 import com.querydsl.collections.CollQuery;
+import com.querydsl.core.NonUniqueResultException;
 import com.querydsl.core.types.EntityPath;
 import com.querydsl.core.types.OrderSpecifier;
 import com.querydsl.core.types.Predicate;
@@ -91,8 +94,13 @@ public class QuerydslKeyValueRepository<T, ID extends Serializable> extends Simp
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#findOne(com.mysema.query.types.Predicate)
 	 */
 	@Override
-	public T findOne(Predicate predicate) {
-		return prepareQuery(predicate).fetchOne();
+	public Optional<T> findOne(Predicate predicate) {
+
+		try {
+			return Optional.ofNullable(prepareQuery(predicate).fetchOne());
+		} catch (NonUniqueResultException o_O) {
+			throw new IncorrectResultSizeDataAccessException("Expected one or no result but found more than one!", 1, o_O);
+		}
 	}
 
 	/*
diff --git a/src/test/java/org/springframework/data/map/QuerydslKeyValueRepositoryUnitTests.java b/src/test/java/org/springframework/data/map/QuerydslKeyValueRepositoryUnitTests.java
index bb07545..9f3990a 100644
--- a/src/test/java/org/springframework/data/map/QuerydslKeyValueRepositoryUnitTests.java
+++ b/src/test/java/org/springframework/data/map/QuerydslKeyValueRepositoryUnitTests.java
@@ -15,12 +15,16 @@
  */
 package org.springframework.data.map;
 
+import static org.assertj.core.api.Assertions.*;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertThat;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.junit.Test;
+import org.springframework.dao.IncorrectResultSizeDataAccessException;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
@@ -49,8 +53,8 @@ public class QuerydslKeyValueRepositoryUnitTests extends AbstractRepositoryUnitT
 
 		repository.saveAll(LENNISTERS);
 
-		Person result = repository.findOne(QPerson.person.firstname.eq(CERSEI.getFirstname()));
-		assertThat(result, is(CERSEI));
+		Optional<Person> result = repository.findOne(QPerson.person.firstname.eq(CERSEI.getFirstname()));
+		assertThat(result).hasValue(CERSEI);
 	}
 
 	@Test // DATACMNS-525
@@ -154,6 +158,15 @@ public class QuerydslKeyValueRepositoryUnitTests extends AbstractRepositoryUnitT
 		assertThat(users, hasItems(CERSEI, JAIME, TYRION));
 	}
 
+	@Test // DATAKV-179
+	public void throwsExceptionIfMoreThanOneResultIsFound() {
+
+		repository.saveAll(LENNISTERS);
+
+		assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class) //
+				.isThrownBy(() -> repository.findOne(person.firstname.contains("e")));
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.map.SimpleKeyValueRepositoryUnitTests#getRepository(org.springframework.data.keyvalue.repository.support.KeyValueRepositoryFactory)