diff --git a/app/assets/javascripts/discourse/components/composer-body.js.es6 b/app/assets/javascripts/discourse/components/composer-body.js.es6
index faee0ef401e..d3c1e96d2eb 100644
--- a/app/assets/javascripts/discourse/components/composer-body.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-body.js.es6
@@ -78,7 +78,7 @@ export default Ember.Component.extend({
 
   @observes('composeState')
   disableFullscreen() {
-    if (this.get('composeState') !== Composer.OPEN) {
+    if (this.get('composeState') !== Composer.OPEN && positioningWorkaround.blur) {
       positioningWorkaround.blur();
     }
   },