@@ -107,7 +107,7 @@ public function append_content_after_template_tag_closer( string $new_content ):
 
 		$bookmark = 'append_content_after_template_tag_closer';
 		$this->set_bookmark( $bookmark );
-		$after_closing_tag = $this->bookmarks[ $bookmark ]->start + $this->bookmarks[ $bookmark ]->length + 1;
+		$after_closing_tag = $this->bookmarks[ $bookmark ]->start + $this->bookmarks[ $bookmark ]->length;
 		$this->release_bookmark( $bookmark );
 
 		// Appends the new content.
@@ -140,7 +140,7 @@ private function get_after_opener_tag_and_before_closer_tag_positions( bool $rew
 		}
 		list( $opener_tag, $closer_tag ) = $bookmarks;
 
-		$after_opener_tag  = $this->bookmarks[ $opener_tag ]->start + $this->bookmarks[ $opener_tag ]->length + 1;
+		$after_opener_tag  = $this->bookmarks[ $opener_tag ]->start + $this->bookmarks[ $opener_tag ]->length;
 		$before_closer_tag = $this->bookmarks[ $closer_tag ]->start;
 
 		if ( $rewind ) {