diff --git a/pkgs/os-specific/linux/syslinux/default.nix b/pkgs/os-specific/linux/syslinux/default.nix
index ce63d383c8e..37a237f57ac 100644
--- a/pkgs/os-specific/linux/syslinux/default.nix
+++ b/pkgs/os-specific/linux/syslinux/default.nix
@@ -30,7 +30,8 @@ stdenv.mkDerivation rec {
   preBuild = ''
     substituteInPlace Makefile --replace /bin/pwd $(type -P pwd)
     substituteInPlace gpxe/src/Makefile.housekeeping --replace /bin/echo $(type -P echo)
-    substituteInPlace utils/ppmtolss16 gpxe/src/Makefile --replace /usr/bin/perl $(type -P perl)
+    substituteInPlace utils/ppmtolss16 --replace /usr/bin/perl $(type -P perl)
+    substituteInPlace gpxe/src/Makefile --replace /usr/bin/perl $(type -P perl)
   '';
 
   stripDebugList = "bin sbin share/syslinux/com32";