diff --git a/system/core/Utf8.php b/system/core/Utf8.php
index 1d5dfc2..ba35674 100644
--- a/system/core/Utf8.php
+++ b/system/core/Utf8.php
@@ -57,17 +57,26 @@
 			&& @ini_get('mbstring.func_overload') != 1	// Multibyte string function overloading cannot be enabled
 			&& $CFG->item('charset') === 'UTF-8'		// Application charset must be UTF-8
 			)
-		{			
+		{
+			define('UTF8_ENABLED', TRUE);
 			log_message('debug', 'UTF-8 Support Enabled');
 
 			// set internal encoding for multibyte string functions if necessary
+			// and set a flag so we don't have to repeatedly use extension_loaded()
+			// or function_exists()
 			if (extension_loaded('mbstring'))
 			{
+				define('MB_ENABLED', TRUE);
 				mb_internal_encoding('UTF-8');
 			}
+			else
+			{
+				define('MB_ENABLED', FALSE);
+			}
 		}
 		else
 		{
+			define('UTF8_ENABLED', FALSE);
 			log_message('debug', 'UTF-8 Support Disabled');
 		}
 	}