diff --git a/app/helpers/projects_helper.rb b/app/helpers/projects_helper.rb
index 07560ce35..a475f2601 100644
--- a/app/helpers/projects_helper.rb
+++ b/app/helpers/projects_helper.rb
@@ -29,4 +29,8 @@ module ProjectsHelper
 
     member&.roles&.last&.name || permission
   end
+
+  def find_user_by_login_or_mail(identifier)
+    (User.find_by_login identifier) || (User.find_by_mail identifier)
+  end
 end
diff --git a/app/views/projects/branches.json.jbuilder b/app/views/projects/branches.json.jbuilder
index 15a51428e..7e299d5e3 100644
--- a/app/views/projects/branches.json.jbuilder
+++ b/app/views/projects/branches.json.jbuilder
@@ -13,7 +13,7 @@ json.array! @branches do |branch|
     json.time_from_now time_from_now(branch['commit']['timestamp'])
   end
 
-  user = User.find_by_login branch['commit']['author']['username']
+  user = find_user_by_login_or_mail(branch['commit']['author']['username'])
   json.author do
     if user
       json.login user.login