diff --git a/pkgs/misc/synaptics/default.nix b/pkgs/misc/synaptics/default.nix
index d4acd9e5f37..dc80035e2d2 100644
--- a/pkgs/misc/synaptics/default.nix
+++ b/pkgs/misc/synaptics/default.nix
@@ -7,7 +7,7 @@ stdenv.mkDerivation {
     md5 = "1102cd575045640a064ab6f9b1e391af";
   };
 
-  makeFlags="DESTDIR=$out PREFIX=/";
+  makeFlags="DESTDIR=\${out} PREFIX=/";
   buildInputs = [libX11 pkgconfig xorgserver libXi libXext];
 
   meta = {