diff --git a/phpBB/includes/message_parser.php b/phpBB/includes/message_parser.php
index 50aad8588a..952b55cc8c 100644
--- a/phpBB/includes/message_parser.php
+++ b/phpBB/includes/message_parser.php
@@ -300,7 +300,7 @@ class bbcode_firstpass extends bbcode
 
 		if ($config['max_' . $this->mode . '_img_height'] || $config['max_' . $this->mode . '_img_width'])
 		{
-			$stats = @getimagesize($in);
+			$stats = @getimagesize(htmlspecialchars_decode($in));
 
 			if ($stats === false)
 			{