diff --git a/krebs/3modules/tinc_graphs.nix b/krebs/3modules/tinc_graphs.nix
index 8390eccbb..486a0c9cc 100644
--- a/krebs/3modules/tinc_graphs.nix
+++ b/krebs/3modules/tinc_graphs.nix
@@ -124,7 +124,7 @@ let
     };
 
     users.extraUsers.tinc_graphs = {
-      uid = genid "tinc_graphs";
+      uid = genid_uint31 "tinc_graphs";
       home = "/var/spool/tinc_graphs";
     };
     services.nginx = mkIf cfg.nginx.enable {