diff --git a/modules/adguard.nix b/modules/adguard.nix
index c0eba2a..7064021 100644
--- a/modules/adguard.nix
+++ b/modules/adguard.nix
@@ -109,7 +109,7 @@ in
                 '') cfg.clients
               )}
         '' + ''
-          + lib.optionalString (cfg.clients == []) ''
+          + lib.optionalString (lib.length cfg.clients == 0) ''
           clients:
             persistent: []