diff --git a/local/o365/db/upgrade.php b/local/o365/db/upgrade.php
index 7aa9e489c..d6445faed 100644
--- a/local/o365/db/upgrade.php
+++ b/local/o365/db/upgrade.php
@@ -303,16 +303,19 @@ function xmldb_local_o365_upgrade($oldversion) {
     }
 
     if ($result && $oldversion < 2015011636.01) {
-        $fieldmapdefault = [
-            'givenName/firstname/always',
-            'surname/lastname/always',
-            'mail/email/always',
-            'city/city/always',
-            'country/country/always',
-            'department/department/always',
-            'preferredLanguage/lang/always',
-        ];
-        set_config('fieldmap', serialize($fieldmapdefault), 'local_o365');
+        $fieldmapconfig = $DB->get_record('config_plugins', ['plugin' => 'local_o365', 'name' => 'fieldmap']);
+        if (empty($fieldmapconfig)) {
+            $fieldmapdefault = [
+                'givenName/firstname/always',
+                'surname/lastname/always',
+                'mail/email/always',
+                'city/city/always',
+                'country/country/always',
+                'department/department/always',
+                'preferredLanguage/lang/always',
+            ];
+            set_config('fieldmap', serialize($fieldmapdefault), 'local_o365');
+        }
         upgrade_plugin_savepoint($result, '2015011636.01', 'local', 'o365');
     }