diff --git a/tasks/prepare.yml b/tasks/prepare.yml
index d0a4ede..ad69d3c 100644
--- a/tasks/prepare.yml
+++ b/tasks/prepare.yml
@@ -23,7 +23,7 @@
         home: "{{ gitea_user_home }}"
         uid: "{{ gitea_uid|default(omit) }}"
         group: "{{ gitea_group }}"
-        groups: "{{ gitea_extra_groups }}"
+        groups: "{{ gitea_extra_groups | join(',') }}"
 
     - name: Install dependencies
       package: