diff --git a/morphia/src/main/java/org/mongodb/morphia/mapping/Mapper.java b/morphia/src/main/java/org/mongodb/morphia/mapping/Mapper.java
index a85d1dd2190..98bef6d08af 100644
--- a/morphia/src/main/java/org/mongodb/morphia/mapping/Mapper.java
+++ b/morphia/src/main/java/org/mongodb/morphia/mapping/Mapper.java
@@ -416,7 +416,10 @@ public Object toMongoObject(final MappedField mf, final MappedClass mc, final Ob
                     if (key == null) {
                         mappedValue = toMongoObject(value, false);
                     } else {
-                        mappedValue = keyToRef(key);
+                        final Reference refAnn = mf.getAnnotation(Reference.class);
+                        mappedValue = refAnn != null && refAnn.idOnly()
+                                      ? keyToManualRef(key)
+                                      : keyToRef(key);
                         if (mappedValue == value) {
                             throw new ValidationException("cannot map to @Reference/Key<T>/DBRef field: " + value);
                         }
diff --git a/morphia/src/test/java/org/mongodb/morphia/mapping/ReferencesNotUsingDBRefTest.java b/morphia/src/test/java/org/mongodb/morphia/mapping/ReferencesNotUsingDBRefTest.java
index 2289ed48e97..881c1f93352 100644
--- a/morphia/src/test/java/org/mongodb/morphia/mapping/ReferencesNotUsingDBRefTest.java
+++ b/morphia/src/test/java/org/mongodb/morphia/mapping/ReferencesNotUsingDBRefTest.java
@@ -216,6 +216,18 @@ public void testNullReferences() {
         getDs().save(container);
         allNull(container);
     }
+    
+    @Test
+    public void testFindByEntityReference() {
+        final Ref ref = new Ref("refId");
+        getDs().save(ref);
+
+        final Container container = new Container();
+        container.singleRef = ref;
+        getDs().save(container);
+        
+        Assert.assertNotNull(getDs().find(Container.class, "singleRef", ref).get());
+    }
 
     private void allNull(final Container container) {
         Assert.assertNull(container.lazyMapRef);