diff --git a/pkgs/development/libraries/qt-4.x/4.8/default.nix b/pkgs/development/libraries/qt-4.x/4.8/default.nix
index cfb4ac61459..4215404a9f6 100644
--- a/pkgs/development/libraries/qt-4.x/4.8/default.nix
+++ b/pkgs/development/libraries/qt-4.x/4.8/default.nix
@@ -154,7 +154,7 @@ stdenv.mkDerivation rec {
 
   NIX_CFLAGS_COMPILE = "-std=gnu++98"
     + optionalString (stdenv.isFreeBSD || stdenv.isDarwin)
-      "-I${glib.dev}/include/glib-2.0 -I${glib.out}/lib/glib-2.0/include"
+      " -I${glib.dev}/include/glib-2.0 -I${glib.out}/lib/glib-2.0/include"
     + optionalString stdenv.isDarwin " -I${libcxx}/include/c++/v1";
 
   NIX_LDFLAGS = optionalString (stdenv.isFreeBSD || stdenv.isDarwin)