diff --git a/sinatra-contrib/spec/respond_with/baz.yajl b/sinatra-contrib/spec/respond_with/baz.yajl
new file mode 100644
index 00000000..5d7e679e
--- /dev/null
+++ b/sinatra-contrib/spec/respond_with/baz.yajl
@@ -0,0 +1 @@
+json = "yajl!"
diff --git a/sinatra-contrib/spec/respond_with_spec.rb b/sinatra-contrib/spec/respond_with_spec.rb
index d7c1492d..1a78b307 100644
--- a/sinatra-contrib/spec/respond_with_spec.rb
+++ b/sinatra-contrib/spec/respond_with_spec.rb
@@ -228,6 +228,12 @@ describe Sinatra::RespondWith do
         req(:pdf).should be_ok
         body.should == "hi"
       end
+
+      it 'uses yajl for json' do
+        respond_with :baz
+        req(:json).should be_ok
+        body.should == "\"yajl!\""
+      end
     end
 
     describe 'customizing' do