diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializer.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializer.java
index 2ab007824..6bd34a6c2 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializer.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializer.java
@@ -20,7 +20,6 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.regex.Pattern;
 
-import com.mongodb.util.JSON;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.data.mongodb.core.convert.QueryMapper;
@@ -31,6 +30,7 @@ import org.springframework.util.ClassUtils;
 
 import com.mongodb.DBObject;
 import com.mongodb.DBRef;
+import com.mongodb.util.JSON;
 import com.querydsl.core.types.Constant;
 import com.querydsl.core.types.Expression;
 import com.querydsl.core.types.Operation;
@@ -116,7 +116,7 @@ class SpringDataMongodbSerializer extends MongodbSerializer {
 	@Override
 	protected DBObject asDBObject(String key, Object value) {
 
-		if (key.endsWith(ID_KEY)) {
+		if (ID_KEY.equals(key) || (key != null && key.endsWith("." + ID_KEY))) {
 			return convertId(key, value);
 		}
 		return super.asDBObject(key, value instanceof Pattern ? value : converter.convertToMongoType(value));
@@ -134,8 +134,7 @@ class SpringDataMongodbSerializer extends MongodbSerializer {
 
 		Object convertedId = mapper.convertId(idValue);
 
-		DBObject mappedIdValue = mapper.getMappedObject(super.asDBObject(key, convertedId),
-				null);
+		DBObject mappedIdValue = mapper.getMappedObject(super.asDBObject(key, convertedId), null);
 		return (DBObject) JSON.parse(JSON.serialize(mappedIdValue));
 	}
 
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializerUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializerUnitTests.java
index bf20640b5..02bc21217 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializerUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializerUnitTests.java
@@ -20,6 +20,7 @@ import static org.junit.Assert.*;
 import static org.springframework.data.mongodb.core.DBObjectTestUtils.*;
 
 import java.util.Collections;
+import java.util.List;
 
 import org.bson.types.ObjectId;
 import org.hamcrest.Matchers;
@@ -50,7 +51,7 @@ import com.querydsl.core.types.dsl.StringPath;
 
 /**
  * Unit tests for {@link SpringDataMongodbSerializer}.
- * 
+ *
  * @author Oliver Gierke
  * @author Christoph Strobl
  */
@@ -158,9 +159,9 @@ public class SpringDataMongodbSerializerUnitTests {
 		DBObject serialized = serializer.asDBObject("_id", new BasicDBObject("$in", objectIds));
 
 		DBObject _id = getAsDBObject(serialized, "_id");
-		Object[] $in = getTypedValue(_id, "$in", Object[].class);
+		List<ObjectId> $in = getTypedValue(_id, "$in", List.class);
 
-		assertThat($in, Matchers.<Object> arrayContaining(firstId, secondId));
+		assertThat($in, contains(firstId, secondId));
 	}
 
 	@Test // DATAMONGO-1485