diff --git a/phpBB/develop/utf_normalizer_test.php b/phpBB/develop/utf_normalizer_test.php
index 2ce74fe833..9c4ad7f5f3 100644
--- a/phpBB/develop/utf_normalizer_test.php
+++ b/phpBB/develop/utf_normalizer_test.php
@@ -20,7 +20,7 @@ if (php_sapi_name() != 'cli')
 // Remove or comment the next line (die(".... ) to enable this script.
 // Do NOT FORGET to either remove this script or disable it after you have used it.
 //
-die("Please read the first lines of this script for instructions on how to enable it");
+//die("Please read the first lines of this script for instructions on how to enable it");
 
 set_time_limit(0);
 error_reporting(E_ALL);
@@ -184,14 +184,14 @@ while (!feof($fp))
 
 	$utf_expected = hex_to_utf($hex_expected);
 
-	if ($utf_expected >= UTF8_SURROGATE_FIRST
-	 && $utf_expected <= UTF8_SURROGATE_LAST)
+	if ($utf_expected >= utf_normalizer::UTF8_SURROGATE_FIRST
+	 && $utf_expected <= utf_normalizer::UTF8_SURROGATE_LAST)
 	{
 		/**
 		* Surrogates are illegal on their own, we expect the normalizer
 		* to return a replacement char
 		*/
-		$utf_expected = UTF8_REPLACEMENT;
+		$utf_expected = utf_normalizer::UTF8_REPLACEMENT;
 		$hex_expected = utf_to_hexseq($utf_expected);
 	}
 
diff --git a/phpBB/includes/utf/utf_normalizer.php b/phpBB/includes/utf/utf_normalizer.php
index 5ed14d4ebb..9048a71e51 100644
--- a/phpBB/includes/utf/utf_normalizer.php
+++ b/phpBB/includes/utf/utf_normalizer.php
@@ -435,7 +435,7 @@ class utf_normalizer
 
 								default:
 									// Five- and six- byte sequences do not need being checked for here anymore
-									if ($utf_char > UTF8_MAX)
+									if ($utf_char > self::UTF8_MAX)
 									{
 										// Out of the Unicode range
 										if ($utf_char[0] < "\xF8")
@@ -1345,7 +1345,7 @@ class utf_normalizer
 								break;
 
 								default:
-									if ($utf_char > UTF8_MAX)
+									if ($utf_char > self::UTF8_MAX)
 									{
 										// Out of the Unicode range
 										$tmp .= substr($str, $tmp_pos, $starter_pos - $tmp_pos);