1 files changed, 10 insertions, 1 deletions
diff --git a/lib/api/api_guard.rb b/lib/api/api_guard.rb
index 9dd2de5c7ba..cb83d22a07f 100644
--- a/lib/api/api_guard.rb
+++ b/lib/api/api_guard.rb
@@ -148,7 +148,16 @@ module API
                 { scope: e.scopes })
             end
 
-          response.finish
+          finished_response = nil
+          response.finish do |rack_response|
+            # Grape expects a Rack::Response
+            # (https://github.com/ruby-grape/grape/commit/c117bff7d22971675f4b34367d3a98bc31c8fc02),
+            # and we need to retrieve it here:
+            # https://github.com/nov/rack-oauth2/blob/40c9a99fd80486ccb8de0e4869ae384547c0d703/lib/rack/oauth2/server/abstract/error.rb#L28
+            finished_response = rack_response
+          end
+
+          finished_response
         end
       end
     end