diff --git a/pkgs/top-level/template-composing+config.nix b/pkgs/top-level/template-composing+config.nix
index 7ff4f3f9d50..172cd9c4797 100644
--- a/pkgs/top-level/template-composing+config.nix
+++ b/pkgs/top-level/template-composing+config.nix
@@ -1,4 +1,4 @@
-args : with args; let localDefs = builderDefs (args // {
+args : with args; let localDefs = builderDefs (args // rec {
 		src = /* put a fetchurl here */
 		(abort "Specify source");
 		useConfig = true;
diff --git a/pkgs/top-level/template-composing-builder.nix b/pkgs/top-level/template-composing-builder.nix
index 276bdc762dc..88bf2b63cfa 100644
--- a/pkgs/top-level/template-composing-builder.nix
+++ b/pkgs/top-level/template-composing-builder.nix
@@ -1,10 +1,10 @@
 args : with args; with builderDefs {src="";} null;
-	let localDefs = builderDefs {
+	let localDefs = builderDefs (rec {
 		src = /* put a fetchurl here */
 
 		buildInputs = [];
 		configureFlags = [];
-	} null; /* null is a terminator for sumArgs */
+	}) null; /* null is a terminator for sumArgs */
 	in with localDefs;
 stdenv.mkDerivation rec {
 	name = "${abort "Specify name"}-"+version;