diff --git a/backup/util/dbops/restore_dbops.class.php b/backup/util/dbops/restore_dbops.class.php
index c4a60131e93..0d826fbba84 100644
--- a/backup/util/dbops/restore_dbops.class.php
+++ b/backup/util/dbops/restore_dbops.class.php
@@ -1215,6 +1215,9 @@ abstract class restore_dbops {
                         $usertag = (object)$usertag;
                         $tags[] = $usertag->rawname;
                     }
+                    if (empty($newuserctxid)) {
+                        $newuserctxid = null; // Tag apis expect a null contextid not 0.
+                    }
                     tag_set('user', $newuserid, $tags, 'core', $newuserctxid);
                 }
 
diff --git a/tag/edit.php b/tag/edit.php
index 3277cd75dac..b2b465501f2 100644
--- a/tag/edit.php
+++ b/tag/edit.php
@@ -136,7 +136,7 @@ if ($tagnew = $tagform->get_data()) {
         }
 
         //updated related tags
-        tag_set('tag', $tagnew->id, explode(',', trim($tagnew->relatedtags)), 'core', $systemcontext);
+        tag_set('tag', $tagnew->id, explode(',', trim($tagnew->relatedtags)), 'core', $systemcontext->id);
         //print_object($tagnew); die();
 
         redirect($CFG->wwwroot.'/tag/index.php?tag='.rawurlencode($tag->name)); // must use $tag here, as the name isn't in the edit form