diff --git a/lib/javascript-static.js b/lib/javascript-static.js
index 94216ace27f..950768eecf0 100644
--- a/lib/javascript-static.js
+++ b/lib/javascript-static.js
@@ -138,6 +138,10 @@ M.util.CollapsibleRegion = function(Y, id, userpref, strtooltip) {
         from: {height:height}
     });
 
+    animation.on('start', () => M.util.js_pending('CollapsibleRegion'));
+    animation.on('resume', () => M.util.js_pending('CollapsibleRegion'));
+    animation.on('pause', () => M.util.js_complete('CollapsibleRegion'));
+
     // Handler for the animation finishing.
     animation.on('end', function() {
         this.div.toggleClass('collapsed');
@@ -152,6 +156,8 @@ M.util.CollapsibleRegion = function(Y, id, userpref, strtooltip) {
         } else {
             this.icon.set('src', M.util.image_url('t/expanded', 'moodle'));
         }
+
+        M.util.js_complete('CollapsibleRegion');
     }, this);
 
     // Hook up the event handler.