diff --git a/spec/controllers/embed_controller_spec.rb b/spec/controllers/embed_controller_spec.rb
index a7ca371c1d3..e81faa03719 100644
--- a/spec/controllers/embed_controller_spec.rb
+++ b/spec/controllers/embed_controller_spec.rb
@@ -108,7 +108,7 @@ describe EmbedController do
     before do
       Fabricate(:embeddable_host)
       Fabricate(:embeddable_host, host: 'http://discourse.org')
-      Fabricate(:embeddable_host, host: 'https://example.com/1234')
+      Fabricate(:embeddable_host, host: 'https://example.com/1234', class_name: 'example')
     end
 
     context "success" do
@@ -130,6 +130,12 @@ describe EmbedController do
         expect(response).to be_success
       end
 
+      it "contains custom class name" do
+        controller.request.stubs(:referer).returns("https://example.com/some-other-path")
+        get :comments, embed_url: embed_url
+        expect(assigns(:embeddable_css_class)).to eq(' class="example"')
+      end
+
       it "doesn't work with a made up host" do
         controller.request.stubs(:referer).returns("http://codinghorror.com/invalid-url")
         get :comments, embed_url: embed_url