diff --git a/class/task.php b/class/task.php
index edc315f..fb12af8 100644
--- a/class/task.php
+++ b/class/task.php
@@ -337,6 +337,8 @@ class MCI_Footnotes_Task {
 		// search footnotes short codes in the content
 		do {
 			// get first occurrence of the footnote short code [start]
+		  $i_int_len_Content = strlen($p_str_Content);
+		  if ($l_int_PosStart > $i_int_len_Content) $l_int_PosStart = $i_int_len_Content;
 			$l_int_PosStart = strpos($p_str_Content, $l_str_StartingTag, $l_int_PosStart);
 			// no short code found, stop here
 			if ($l_int_PosStart === false) {