diff --git a/lib/active_model/serializer/associations.rb b/lib/active_model/serializer/associations.rb
index aa77bf63..e2e13c22 100644
--- a/lib/active_model/serializer/associations.rb
+++ b/lib/active_model/serializer/associations.rb
@@ -95,11 +95,7 @@ module ActiveModel
         end
 
         def embeddable?
-          if polymorphic? && object.nil?
-            false
-          else
-            true
-          end
+          super || !polymorphic?
         end
 
         def serializables