diff --git a/nixos/hosts/ingress-proxy/default.nix b/nixos/hosts/ingress-proxy/default.nix
index 8ba08bb..984e8bd 100644
--- a/nixos/hosts/ingress-proxy/default.nix
+++ b/nixos/hosts/ingress-proxy/default.nix
@@ -33,7 +33,7 @@ in {
         serverAliases = aliases;
 
         root = pkgs.stdenvNoCC.mkDerivation {
-          src = src ? pkgs.lib.fetchGit { inherit url ref; };
+          src = if src then src else pkgs.lib.fetchGit { inherit url ref; };
           installPhase = "cp -r $src $out";
         };
       };