diff --git a/mod/quiz/locallib.php b/mod/quiz/locallib.php
index 929ae1a9d89..ec50118835e 100644
--- a/mod/quiz/locallib.php
+++ b/mod/quiz/locallib.php
@@ -138,7 +138,7 @@ function quiz_first_questionnumber($quizlayout, $pagelayout) {
     // this works by finding all the questions from the quizlayout that
     // come before the current page and then adding up their lengths.
     global $CFG;
-    $start = strpos($quizlayout, $pagelayout)-3;
+    $start = strpos($quizlayout, ','.$pagelayout.',')-2;
     if ($start > 0) {
         $prevlist = substr($quizlayout, 0, $start);
         return get_field_sql("SELECT sum(length)+1 FROM {$CFG->prefix}quiz_questions