--- build/linux/unbundle/zlib.gn.orig	2016-05-30 13:09:56.987716771 +0000
+++ build/linux/unbundle/zlib.gn	2016-05-30 13:12:36.879014187 +0000
@@ -9,11 +9,16 @@
   headers = [ "zlib.h" ]
 }
 
+config("system_zlib") {
+  defines = [ "USE_SYSTEM_ZLIB=1" ]
+}
+
 source_set("zlib") {
   deps = [
     ":zlib_shim",
   ]
   libs = [ "z" ]
+  public_configs = [ ":system_zlib" ]
 }
 
 shim_headers("minizip_shim") {