diff --git a/app/controllers/concerns/oauth_applications.rb b/app/controllers/concerns/oauth_applications.rb
index 7210ed3eb32306c6c2422c4531cc1579b7c1b95b..9849aa93fa61a29830c77d95ff368ced63edac7c 100644
--- a/app/controllers/concerns/oauth_applications.rb
+++ b/app/controllers/concerns/oauth_applications.rb
@@ -6,7 +6,7 @@ module OauthApplications
   end
 
   def prepare_scopes
-    scopes = params.dig(:doorkeeper_application, :scopes)
+    scopes = params.fetch(:doorkeeper_application, {}).fetch(:scopes, nil)
 
     if scopes
       params[:doorkeeper_application][:scopes] = scopes.join(' ')