diff --git a/src/InputFilter.php b/src/InputFilter.php
index e7f0bbdf..e3e8839b 100644
--- a/src/InputFilter.php
+++ b/src/InputFilter.php
@@ -410,7 +410,7 @@ protected function cleanTags($source)
 
 			if (($tagOpenNested !== false) && ($tagOpenNested < $tagOpenEnd))
 			{
-				$preTag       .= StringHelper::substr($postTag, 0, ($tagOpenNested + 1));
+				$preTag       .= StringHelper::substr($postTag, 1, $tagOpenNested);
 				$postTag      = StringHelper::substr($postTag, ($tagOpenNested + 1));
 				$tagOpenStart = StringHelper::strpos($postTag, '<');