diff --git a/admin/qbehaviours.php b/admin/qbehaviours.php
index 9edd3f09522..e8b87b712b3 100644
--- a/admin/qbehaviours.php
+++ b/admin/qbehaviours.php
@@ -88,10 +88,9 @@ if (($disable = optional_param('disable', '', PARAM_PLUGIN)) && confirm_sesskey(
     }
 
     if (array_search($disable, $disabledbehaviours) === false) {
-        $disabledbehaviours[] = $disable;
-        set_config('disabledbehaviours', implode(',', $disabledbehaviours), 'question');
+        $class = \core_plugin_manager::resolve_plugininfo_class('qbehaviour');
+        $class::enable_plugin($disable, false);
     }
-    core_plugin_manager::reset_caches();
     redirect($thispageurl);
 }
 
@@ -106,10 +105,9 @@ if (($enable = optional_param('enable', '', PARAM_PLUGIN)) && confirm_sesskey())
     }
 
     if (($key = array_search($enable, $disabledbehaviours)) !== false) {
-        unset($disabledbehaviours[$key]);
-        set_config('disabledbehaviours', implode(',', $disabledbehaviours), 'question');
+        $class = \core_plugin_manager::resolve_plugininfo_class('qbehaviour');
+        $class::enable_plugin($enable, true);
     }
-    core_plugin_manager::reset_caches();
     redirect($thispageurl);
 }
 
@@ -238,4 +236,3 @@ function question_behaviour_icon_html($action, $behaviour, $icon, $alt, $tip) {
             new pix_icon($icon, $alt, 'moodle', array('title' => '', 'class' => 'iconsmall')),
             null, array('title' => $tip));
 }
-
diff --git a/lib/classes/plugininfo/qbehaviour.php b/lib/classes/plugininfo/qbehaviour.php
index 85de13462a8..01220dcbb9d 100644
--- a/lib/classes/plugininfo/qbehaviour.php
+++ b/lib/classes/plugininfo/qbehaviour.php
@@ -57,6 +57,33 @@ class qbehaviour extends base {
         return $enabled;
     }
 
+    public static function enable_plugin(string $pluginname, int $enabled): bool {
+        $haschanged = false;
+        $plugins = [];
+        $oldvalue = get_config('question', 'disabledbehaviours');
+        if (!empty($oldvalue)) {
+            $plugins = array_flip(explode(',', $oldvalue));
+        }
+        // Only set visibility if it's different from the current value.
+        if ($enabled && array_key_exists($pluginname, $plugins)) {
+            unset($plugins[$pluginname]);
+            $haschanged = true;
+        } else if (!$enabled && !array_key_exists($pluginname, $plugins)) {
+            $plugins[$pluginname] = $pluginname;
+            $haschanged = true;
+        }
+
+        if ($haschanged) {
+            $new = implode(',', array_flip($plugins));
+            add_to_config_log('disabledbehaviours', $oldvalue, $new, 'question');
+            set_config('disabledbehaviours', $new, 'question');
+            // Reset caches.
+            \core_plugin_manager::reset_caches();
+        }
+
+        return $haschanged;
+    }
+
     public function is_uninstall_allowed() {
         global $DB;
 
@@ -110,4 +137,3 @@ class qbehaviour extends base {
         return new moodle_url('/admin/qbehaviours.php');
     }
 }
-