diff --git a/pkgs/tools/misc/mc/default.nix b/pkgs/tools/misc/mc/default.nix
index cddda2c6a62f..cb577ee333d5 100644
--- a/pkgs/tools/misc/mc/default.nix
+++ b/pkgs/tools/misc/mc/default.nix
@@ -57,10 +57,12 @@ stdenv.mkDerivation rec {
       --replace /bin/rm ${coreutils}/bin/rm
   '';
 
-  postFixup = ''
+  preFixup = ''
     # remove unwanted build-dependency references
     sed -i -e "s!PKG_CONFIG_PATH=''${PKG_CONFIG_PATH}!PKG_CONFIG_PATH=$(echo "$PKG_CONFIG_PATH" | sed -e 's/./0/g')!" $out/bin/mc
-  '' + lib.optionalString (!stdenv.isDarwin) ''
+  '';
+
+  postFixup = lib.optionalString (!stdenv.isDarwin) ''
     # libX11.so is loaded dynamically so autopatch doesn't detect it
     patchelf \
       --add-needed ${libX11}/lib/libX11.so \