diff --git a/api/index.php b/api/index.php
index b8a6d4c4a5807f924879abb4b97c19de54710fd2..fd59f4bee94ede410e32e8c51de4da953739da99 100644
--- a/api/index.php
+++ b/api/index.php
@@ -21,7 +21,9 @@
 
 	chdir("..");
 
-	if (defined('ENABLE_GZIP_OUTPUT') && ENABLE_GZIP_OUTPUT) {
+	if (defined('ENABLE_GZIP_OUTPUT') && ENABLE_GZIP_OUTPUT &&
+			function_exists("ob_gzhandler")) {
+
 		ob_start("ob_gzhandler");
 	}
 
diff --git a/backend.php b/backend.php
index 1337db5c2e86cc8eca2d57ba3246cacd4ad0152e..efc3793d303213ff0c0ef349392f988b52383653 100644
--- a/backend.php
+++ b/backend.php
@@ -56,7 +56,7 @@
 
 	header("Content-Type: text/plain; charset=utf-8");
 
-	if (ENABLE_GZIP_OUTPUT) {
+	if (ENABLE_GZIP_OUTPUT && function_exists("ob_gzhandler")) {
 		ob_start("ob_gzhandler");
 	}
 
diff --git a/public.php b/public.php
index 8ffc83224f170a51c3a89f175848e6bccdb291f4..675a9e352d9a6a413b60045c661695e82a9c9095 100644
--- a/public.php
+++ b/public.php
@@ -1,5 +1,5 @@
 <?php
-	set_include_path(get_include_path() . PATH_SEPARATOR . 
+	set_include_path(get_include_path() . PATH_SEPARATOR .
 		dirname(__FILE__) . "/include");
 
 	/* remove ill effects of magic quotes */
@@ -34,7 +34,7 @@
 
 	if (!init_connection($link)) return;
 
-	if (ENABLE_GZIP_OUTPUT) {
+	if (ENABLE_GZIP_OUTPUT && function_exists("ob_gzhandler")) {
 		ob_start("ob_gzhandler");
 	}