diff --git a/lib/ontologies_linked_data/models/users/oauth_authentication.rb b/lib/ontologies_linked_data/models/users/oauth_authentication.rb
index d4f4ec75..9ad23206 100644
--- a/lib/ontologies_linked_data/models/users/oauth_authentication.rb
+++ b/lib/ontologies_linked_data/models/users/oauth_authentication.rb
@@ -133,7 +133,7 @@ def auth_github(token)
           def user_from_keycloak_data(user_data)
             {
               email: user_data['email'],
-              username: user_data['preferred_username'],
+              username: user_data['email'].split('@').first,
               firstName: user_data['given_name'],
               lastName: user_data['family_name']
             }