diff --git a/nixos/modules/services/web-apps/mattermost.nix b/nixos/modules/services/web-apps/mattermost.nix
index 20d21c008c29..bf3a8eed6004 100644
--- a/nixos/modules/services/web-apps/mattermost.nix
+++ b/nixos/modules/services/web-apps/mattermost.nix
@@ -37,7 +37,7 @@ in
         type = types.str;
         example = "https://chat.example.com";
         description = ''
-          URL this Mattermost instance is reachable under, without trailing slash."
+          URL this Mattermost instance is reachable under, without trailing slash.
         '';
       };