diff --git a/lib/travis/api/app/endpoint/authorization.rb b/lib/travis/api/app/endpoint/authorization.rb
index 6b511de8..29dec476 100644
--- a/lib/travis/api/app/endpoint/authorization.rb
+++ b/lib/travis/api/app/endpoint/authorization.rb
@@ -91,6 +91,7 @@ class Travis::Api::App
       get '/handshake' do
         handshake do |user, token, redirect_uri|
           if target_ok? redirect_uri
+            content_type :html
             data = { user: user, token: token, uri: redirect_uri }
             erb(:post_payload, locals: data)
           else