diff --git a/nixos/modules/services/web-apps/stash.nix b/nixos/modules/services/web-apps/stash.nix
index 60c8ad8a8eb4..47f66edb7ddb 100644
--- a/nixos/modules/services/web-apps/stash.nix
+++ b/nixos/modules/services/web-apps/stash.nix
@@ -225,7 +225,7 @@ let
       };
       gallery_cover_regex = mkOption {
         type = types.str;
-        default = "(poster|cover|folder|board)\.[^\.]+$";
+        default = "(poster|cover|folder|board)\\.[^.]+$";
         description = "Regex used to identify images as gallery covers";
       };
       no_proxy = mkOption {