diff --git a/pkgs/development/compilers/gcc/4.9/default.nix b/pkgs/development/compilers/gcc/4.9/default.nix
index 7e6c4a5fe4f..1e27546af63 100644
--- a/pkgs/development/compilers/gcc/4.9/default.nix
+++ b/pkgs/development/compilers/gcc/4.9/default.nix
@@ -303,7 +303,6 @@ stdenv.mkDerivation ({
     configureFlagsArray+=(
       --with-sysroot="${stdenv.libc}"
       --with-native-system-header-dir=/include
-      CFLAGS_FOR_BUILD=
     )
   '';