diff --git a/pkgs/development/libraries/libAfterImage/default.nix b/pkgs/development/libraries/libAfterImage/default.nix
index 3bbbe49eb294..a569b59621e0 100644
--- a/pkgs/development/libraries/libAfterImage/default.nix
+++ b/pkgs/development/libraries/libAfterImage/default.nix
@@ -81,7 +81,8 @@ stdenv.mkDerivation {
     "--disable-mmx-optimization"
     "--${if static then "enable" else "disable"}-staticlibs"
     "--${if !static then "enable" else "disable"}-sharedlibs"
-  ] ++ lib.optional withX "--with-x";
+    "--${if withX then "with" else "without"}-x"
+  ];
 
   meta = with lib; {
     homepage = "http://www.afterstep.org/afterimage/";