diff --git a/test/adapter/json/has_many_test.rb b/test/adapter/json/has_many_test.rb
index eeff41df..a88b2f54 100644
--- a/test/adapter/json/has_many_test.rb
+++ b/test/adapter/json/has_many_test.rb
@@ -38,7 +38,7 @@ module ActiveModel
               tags: [
                 {"attributes"=>{"id"=>1, "name"=>"#hash_tag"}}
               ]
-            }, adapter.serializable_hash[:post_with_tags])
+            }.to_json, adapter.serializable_hash[:post_with_tags].to_json)
           end
         end
       end
diff --git a/test/serializers/associations_test.rb b/test/serializers/associations_test.rb
index f92e5a90..04681d2c 100644
--- a/test/serializers/associations_test.rb
+++ b/test/serializers/associations_test.rb
@@ -71,7 +71,7 @@ module ActiveModel
         PostWithTagsSerializer.new(@post).each_association do |name, serializer, options|
           assert_equal name, :tags
           assert_equal serializer, nil
-          assert_equal [{ attributes: { name: "#hashtagged" }}].as_json, options[:virtual_value]
+          assert_equal [{ attributes: { name: "#hashtagged" }}].to_json, options[:virtual_value].to_json
         end
       end