diff --git a/addon/transforms/fragment-array.js b/addon/transforms/fragment-array.js
index 56b1fc3e..c7cd25dd 100644
--- a/addon/transforms/fragment-array.js
+++ b/addon/transforms/fragment-array.js
@@ -31,7 +31,7 @@ const FragmentArrayTransform = FragmentTransform.extend({
     let store = this.store;
 
     return snapshots.map(snapshot => {
-      let serializer = store.serializerFor(snapshot.modelName);
+      let serializer = store.serializerFor(snapshot.modelName || snapshot.constructor.modelName);
       return serializer.serialize(snapshot);
     });
   }
diff --git a/addon/transforms/fragment.js b/addon/transforms/fragment.js
index d62dfc59..8b080a73 100644
--- a/addon/transforms/fragment.js
+++ b/addon/transforms/fragment.js
@@ -35,7 +35,7 @@ const FragmentTransform = Transform.extend({
     }
 
     let store = this.store;
-    let serializer = store.serializerFor(snapshot.modelName);
+    let serializer = store.serializerFor(snapshot.modelName || snapshot.constructor.modelName);
 
     return serializer.serialize(snapshot);
   },