diff --git a/proxy.php b/proxy.php
index 053c6ce..aa4f629 100644
--- a/proxy.php
+++ b/proxy.php
@@ -4,10 +4,11 @@
 // Released under MIT license
 // Free Software should work like this: whatever you take for free, you must give back for free.
 
-ob_start("ob_gzhandler");
-
+if (!function_exists("gzcompress")) die ("This proxy requires PHP's zlib extension. Please install/enable it on your server and try again.");
 if (!function_exists("curl_init")) die ("This proxy requires PHP's cURL extension. Please install/enable it on your server and try again.");
 
+ob_start("ob_gzhandler");
+
 //Adapted from http://www.php.net/manual/en/function.getallheaders.php#99814
 if (!function_exists("getallheaders")) {
   function getallheaders() {