diff --git a/mod/wiki/files.php b/mod/wiki/files.php
index 377ed741afb..fe92ac5fb5d 100644
--- a/mod/wiki/files.php
+++ b/mod/wiki/files.php
@@ -49,6 +49,11 @@ if ($wid) {
         print_error('incorrectwikiid', 'wiki');
     }
     if (!$subwiki = wiki_get_subwiki_by_group($wiki->id, $currentgroup, $userid)) {
+        // trap anomalous parameters that would lead to a shared subwiki being created for an individual user
+        if ($wiki->wikimode == 'individual' && $userid == 0) {
+            throw new coding_exception('Tried creating a shared subwiki in \'individual\' mode. This shouldn\'t happen.');
+        }
+
         // create subwiki if doesn't exist
         $subwikiid = wiki_add_subwiki($wiki->id, $currentgroup, $userid);
         $subwiki = wiki_get_subwiki($subwikiid);
diff --git a/mod/wiki/pagelib.php b/mod/wiki/pagelib.php
index 54e710f59a7..703946d64df 100644
--- a/mod/wiki/pagelib.php
+++ b/mod/wiki/pagelib.php
@@ -947,8 +947,13 @@ class page_wiki_create extends page_wiki {
             $groupid = '0';
         }
         if (empty($this->subwiki)) {
+            // trap anomalous parameters that would lead to a shared subwiki being created for an individual user
+            if ($PAGE->activityrecord->wikimode == 'individual' && $this->uid == 0) {
+                throw new coding_exception('Tried creating a shared subwiki in \'individual\' mode. This shouldn\'t happen.');
+            }
+
             // If subwiki is not set then try find one and set else create one.
-            if (!$this->subwiki = wiki_get_subwiki_by_group($this->wid, $groupid)) {
+            if (!$this->subwiki = wiki_get_subwiki_by_group($this->wid, $groupid, $this->uid)) {
                 $swid = wiki_add_subwiki($PAGE->activityrecord->id, $groupid, $this->uid);
                 $this->subwiki = wiki_get_subwiki($swid);
             }