diff --git a/Michelf/MarkdownExtra.php b/Michelf/MarkdownExtra.php
index 918cfc7..1516f45 100644
--- a/Michelf/MarkdownExtra.php
+++ b/Michelf/MarkdownExtra.php
@@ -611,7 +611,7 @@ class MarkdownExtra extends \Michelf\Markdown {
 				// Increase/decrease nested tag count.
 				if ($tag[1] === '/') {
 					$depth--;
-				} else if ($tag{strlen($tag)-2} !== '/') {
+				} else if ($tag[strlen($tag)-2] !== '/') {
 					$depth++;
 				}
 
@@ -734,7 +734,7 @@ class MarkdownExtra extends \Michelf\Markdown {
 				if (preg_match('{^</?' . $base_tag_name_re . '\b}', $tag)) {
 					if ($tag[1] === '/') {
 						$depth--;
-					} else if ($tag{strlen($tag)-2} !== '/') {
+					} else if ($tag[strlen($tag)-2] !== '/') {
 						$depth++;
 					}
 				}