diff --git a/pkgs/development/libraries/zlib/default.nix b/pkgs/development/libraries/zlib/default.nix
index 6dec5bac1fe..ca7bc7c7e41 100644
--- a/pkgs/development/libraries/zlib/default.nix
+++ b/pkgs/development/libraries/zlib/default.nix
@@ -2,7 +2,6 @@
 
 stdenv.mkDerivation {
   name = "zlib-1.2.1";
-  builder = ./builder.sh;
   src = fetchurl {
     url = http://www.gzip.org/zlib/zlib-1.2.1.tar.gz;
     md5 = "ef1cb003448b4a53517b8f25adb12452";