diff --git a/modules/services/mbsync.nix b/modules/services/mbsync.nix
index 5c994cc6b..a78975368 100644
--- a/modules/services/mbsync.nix
+++ b/modules/services/mbsync.nix
@@ -71,7 +71,7 @@ in
     postExec = mkOption {
       type = types.nullOr types.str;
       default = null;
-      example = "mu index";
+      example = "\${pkgs.mu}/bin/mu index";
       description = ''
         An optional command to run after mbsync executes successfully.
         This is useful for running mailbox indexing tools.