diff --git a/system/libraries/Cache/Cache.php b/system/libraries/Cache/Cache.php
index 215a7c5..06403b6 100644
--- a/system/libraries/Cache/Cache.php
+++ b/system/libraries/Cache/Cache.php
@@ -243,14 +243,13 @@
 	 */
 	public function is_supported($driver)
 	{
-		static $support = array();
+		static $support;
 
-		if ( ! isset($support[$driver]))
+		if ( ! isset($support, $support[$driver]))
 		{
 			$support[$driver] = $this->{$driver}->is_supported();
 		}
 
 		return $support[$driver];
 	}
-
 }