diff --git a/pkgs/tools/X11/xdg-utils/default.nix b/pkgs/tools/X11/xdg-utils/default.nix
index 7ba20480b6f5..24b9096d27c6 100644
--- a/pkgs/tools/X11/xdg-utils/default.nix
+++ b/pkgs/tools/X11/xdg-utils/default.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
       substituteInPlace $item --replace "cut " "${coreutils}/bin/cut "
       substituteInPlace $item --replace "sed " "${gnused}/bin/sed "
       substituteInPlace $item --replace "egrep " "${gnugrep}/bin/egrep "
-      sed -i $item -e "s#[^e]grep #${gnugrep}/bin/grep #g" # Don't replace 'egrep'
+      sed -i $item -re "s#([^e])grep #\1${gnugrep}/bin/grep #g" # Don't replace 'egrep'
       substituteInPlace $item --replace "which " "${which}/bin/which "
       substituteInPlace $item --replace "/usr/bin/file" "${file}/bin/file"
     done