diff --git a/Free Learning/CHANGEDB.php b/Free Learning/CHANGEDB.php
index d93fc58..a1a0e98 100644
--- a/Free Learning/CHANGEDB.php	
+++ b/Free Learning/CHANGEDB.php	
@@ -2193,4 +2193,9 @@
 //v5.21.12
 ++$count;
 $sql[$count][0] = '5.21.12';
-$sql[$count][1] = "";
\ No newline at end of file
+$sql[$count][1] = "";
+
+//v5.21.13
+++$count;
+$sql[$count][0] = '5.21.13';
+$sql[$count][1] = "";
diff --git a/Free Learning/CHANGELOG.txt b/Free Learning/CHANGELOG.txt
index 14cf725..9c681ba 100644
--- a/Free Learning/CHANGELOG.txt	
+++ b/Free Learning/CHANGELOG.txt	
@@ -1,5 +1,9 @@
 CHANGELOG
 =========
+v5.21.13
+--------
+Fixed copy to markbook creating duplicate records in classes with more than one teacher
+
 v5.21.12
 --------
 Adjusted links in unit Resources tab to open in new tab
diff --git a/Free Learning/manifest.php b/Free Learning/manifest.php
index b549620..3ce8aeb 100644
--- a/Free Learning/manifest.php	
+++ b/Free Learning/manifest.php	
@@ -25,7 +25,7 @@
 $entryURL = 'units_browse.php';
 $type = 'Additional';
 $category = 'Learn';
-$version = '5.21.12';
+$version = '5.21.13';
 $author = 'Ross Parker';
 $url = 'http://rossparker.org/free-learning';
 
diff --git a/Free Learning/units_browse_details_approvalProcess.php b/Free Learning/units_browse_details_approvalProcess.php
index 369e015..371384d 100644
--- a/Free Learning/units_browse_details_approvalProcess.php	
+++ b/Free Learning/units_browse_details_approvalProcess.php	
@@ -274,7 +274,7 @@
                                 $markbookEntryGateway = $container->get(MarkbookEntryGateway::class);
 
                                 foreach ($gibbonPersonIDStudents AS $gibbonPersonIDStudent) {
-                                    $gibbonMarkbookEntry = $markbookEntryGateway->selectBy(['gibbonMarkbookColumnID' => $gibbonMarkbookColumnID, 'gibbonPersonIDStudent' => $gibbonPersonIDStudent, 'gibbonPersonIDLastEdit' => $session->get('gibbonPersonID')]);
+                                    $gibbonMarkbookEntry = $markbookEntryGateway->selectBy(['gibbonMarkbookColumnID' => $gibbonMarkbookColumnID, 'gibbonPersonIDStudent' => $gibbonPersonIDStudent]);
 
                                     if ($gibbonMarkbookEntry->rowCount() == 1) { // Update existing row
                                         $gibbonMarkbookEntryID = $gibbonMarkbookEntry->fetch()['gibbonMarkbookEntryID'];
diff --git a/Free Learning/version.php b/Free Learning/version.php
index 1016ee2..72cbc2c 100755
--- a/Free Learning/version.php	
+++ b/Free Learning/version.php	
@@ -20,5 +20,5 @@
 /**
  * Sets version information.
  */
-$moduleVersion = '5.21.12';
+$moduleVersion = '5.21.13';
 $coreVersion = '24.0.00';