diff --git a/enrol/mnet/enrol.php b/enrol/mnet/enrol.php
index 263b2ec8f46..d58dbfa9260 100644
--- a/enrol/mnet/enrol.php
+++ b/enrol/mnet/enrol.php
@@ -149,7 +149,7 @@ class enrolment_plugin_mnet {
 
 
             if (!empty($CFG->enrol_mnet_allowed_courses)) {
-                $where .=  " OR co.id in ('{$CFG->enrol_mnet_allowed_courses}') ";
+                $where .=  " OR co.id in ({$CFG->enrol_mnet_allowed_courses}) ";
             }
 
             $where .= ')';