diff --git a/mod/assign/assignmentplugin.php b/mod/assign/assignmentplugin.php
index 69b6ec4e653..dcb31e96b72 100644
--- a/mod/assign/assignmentplugin.php
+++ b/mod/assign/assignmentplugin.php
@@ -344,7 +344,7 @@ abstract class assign_plugin {
      * @param bool $showviewlink Modifed to return whether or not to show a link to the full submission/feedback
      * @return string - return a string representation of the submission in full
      */
-    public function view_summary(stdClass $submissionorgrade, $showviewlink) {
+    public function view_summary(stdClass $submissionorgrade, & $showviewlink) {
         return '';
     }
 
diff --git a/mod/assign/feedback/comments/locallib.php b/mod/assign/feedback/comments/locallib.php
index 7f97175c00e..dadd2a86680 100644
--- a/mod/assign/feedback/comments/locallib.php
+++ b/mod/assign/feedback/comments/locallib.php
@@ -105,7 +105,7 @@ class assign_feedback_comments extends assign_feedback_plugin {
      * @param bool $showviewlink Set to true to show a link to view the full feedback
      * @return string
      */
-    public function view_summary(stdClass $grade, $showviewlink) {
+    public function view_summary(stdClass $grade, & $showviewlink) {
         $feedbackcomments = $this->get_feedback_comments($grade->id);
         if ($feedbackcomments) {
             $text = format_text($feedbackcomments->commenttext, $feedbackcomments->commentformat, array('context' => $this->assignment->get_context()));
diff --git a/mod/assign/feedback/file/locallib.php b/mod/assign/feedback/file/locallib.php
index 20c4be7ca1d..9989cf328ae 100644
--- a/mod/assign/feedback/file/locallib.php
+++ b/mod/assign/feedback/file/locallib.php
@@ -146,7 +146,7 @@ class assign_feedback_file extends assign_feedback_plugin {
      * @param bool $showviewlink - Set to true to show a link to see the full list of files
      * @return string
      */
-    public function view_summary(stdClass $grade, $showviewlink) {
+    public function view_summary(stdClass $grade, & $showviewlink) {
         $count = $this->count_files($grade->id, ASSIGNFEEDBACK_FILE_FILEAREA);
         // show a view all link if the number of files is over this limit
         $showviewlink = $count > ASSIGNFEEDBACK_FILE_MAXSUMMARYFILES;
diff --git a/mod/assign/submission/comments/locallib.php b/mod/assign/submission/comments/locallib.php
index 43ee80da72b..eb879388757 100644
--- a/mod/assign/submission/comments/locallib.php
+++ b/mod/assign/submission/comments/locallib.php
@@ -53,7 +53,7 @@ class assign_submission_comments extends assign_submission_plugin {
     * @param bool $showviewlink - If the comments are long this is set to true so they can be shown in a separate page
     * @return string
     */
-   public function view_summary(stdClass $submission, $showviewlink) {
+   public function view_summary(stdClass $submission, & $showviewlink) {
 
         // never show a link to view full submission
         $showviewlink = false;
diff --git a/mod/assign/submission/file/locallib.php b/mod/assign/submission/file/locallib.php
index b097c397301..3f95f343524 100644
--- a/mod/assign/submission/file/locallib.php
+++ b/mod/assign/submission/file/locallib.php
@@ -244,7 +244,7 @@ class assign_submission_file extends assign_submission_plugin {
      * @param bool $showviewlink Set this to true if the list of files is long
      * @return string
      */
-    public function view_summary(stdClass $submission, $showviewlink) {
+    public function view_summary(stdClass $submission, & $showviewlink) {
         $count = $this->count_files($submission->id, ASSIGNSUBMISSION_FILE_FILEAREA);
 
         // show we show a link to view all files for this plugin?
diff --git a/mod/assign/submission/onlinetext/locallib.php b/mod/assign/submission/onlinetext/locallib.php
index dcaf0c5531a..0ab3777664e 100644
--- a/mod/assign/submission/onlinetext/locallib.php
+++ b/mod/assign/submission/onlinetext/locallib.php
@@ -192,7 +192,7 @@ class assign_submission_onlinetext extends assign_submission_plugin {
       * @param bool $showviewlink - If the summary has been truncated set this to true
       * @return string
       */
-    public function view_summary(stdClass $submission, $showviewlink) {
+    public function view_summary(stdClass $submission, & $showviewlink) {
 
         $onlinetextsubmission = $this->get_onlinetext_submission($submission->id);
         // always show the view link