diff --git a/pkgs/tools/backup/bup/default.nix b/pkgs/tools/backup/bup/default.nix
index 22f41c2b0c1..3908b4984c4 100644
--- a/pkgs/tools/backup/bup/default.nix
+++ b/pkgs/tools/backup/bup/default.nix
@@ -31,7 +31,6 @@ stdenv.mkDerivation {
   postPatch = ''
     patchShebangs .
     substituteInPlace Makefile --replace "-Werror" ""
-    substituteInPlace Makefile --replace "./format-subst.pl" "${perl}/bin/perl ./format-subst.pl"
   '' + optionalString par2Support ''
     substituteInPlace cmd/fsck-cmd.py --replace "'par2'" "'${par2cmdline}/bin/par2'"
   '';