diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
index 3e39e8af2..c350e0b74 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
@@ -568,7 +568,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 				// Don't use conversion service here as removal of ObjectToString converter results in some primitive types not
 				// being convertable
 				String simpleKey = key.toString();
-				if (conversions.isSimpleType(val.getClass())) {
+				if (val == null || conversions.isSimpleType(val.getClass())) {
 					writeSimpleInternal(simpleKey, val, dbo);
 				} else {
 					DBObject newDbo = new BasicDBObject();
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java
index 154d0c347..1781f5e0d 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java
@@ -491,6 +491,23 @@ public class MappingMongoConverterUnitTests {
 		
 	}
 	
+	/**
+	 * @see DATADOC-228
+	 */
+	@Test
+	public void writesNullValuesForMaps() {
+		
+		ClassWithMapProperty foo = new ClassWithMapProperty();
+		foo.map = Collections.singletonMap(Locale.US, null);
+		
+		DBObject result = new BasicDBObject();
+		converter.write(foo, result);
+		
+		Object map = result.get("map");
+		assertThat(map, is(instanceOf(DBObject.class)));
+		assertThat(((DBObject) map).keySet(), hasItem("en_US"));
+	}
+	
 	class GenericType<T> {
 		T content;
 	}