diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/convert/MappingMongoConverter.java b/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/convert/MappingMongoConverter.java
index 49911ad60..50b1d4c45 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/convert/MappingMongoConverter.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/convert/MappingMongoConverter.java
@@ -306,7 +306,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		return instance;
 	}
 
-	public void write(final Object obj, final DBObject dbo) {
+	@SuppressWarnings("unchecked")
+  public void write(final Object obj, final DBObject dbo) {
 		if (null == obj) {
 			return;
 		}
@@ -318,6 +319,11 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			dbo.putAll(result);
 			return;
 		}
+		
+		if (Map.class.isAssignableFrom(obj.getClass())) {
+		  writeMapInternal((Map<Object, Object>) obj, dbo);
+		  return;
+		}
 
 		PersistentEntity<?> entity = mappingContext.getPersistentEntity(obj.getClass());
 		write(obj, dbo, entity);
@@ -508,7 +514,9 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			Object key = entry.getKey();
 			Object val = entry.getValue();
 			if (isSimpleType(key.getClass())) {
-				String simpleKey = conversionService.convert(key, String.class);
+        // Don't use conversion service here as removal of ObjectToString converter results in some primitive types not
+        // being convertable
+				String simpleKey = key.toString();
 				if (isSimpleType(val.getClass())) {
 					dbo.put(simpleKey, val);
 				} else {
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/mapping/MappingMongoConverterUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/mapping/MappingMongoConverterUnitTests.java
index 83b43115c..88443700f 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/mapping/MappingMongoConverterUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/mapping/MappingMongoConverterUnitTests.java
@@ -20,8 +20,12 @@ import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
 import org.joda.time.LocalDate;
 import org.junit.Before;
 import org.junit.Test;
@@ -90,7 +94,20 @@ public class MappingMongoConverterUnitTests {
     Person result = converter.read(Person.class, dbObject);
     assertThat(result.birthDate, is(notNullValue()));
   }
-  
+
+  /**
+   * @see DATADOC-130
+   */
+  @Test
+  public void convertsMapTypeCorrectly() {
+    
+    Map<Locale, String> map = Collections.singletonMap(Locale.US, "Foo");
+    
+    BasicDBObject dbObject = new BasicDBObject();
+    converter.write(map, dbObject);
+    
+    assertThat(dbObject.get(Locale.US.toString()).toString(), is("Foo"));
+  }
   
   public static class Address {
     String street;