diff --git a/core/modules/editor/engines/simple.js b/core/modules/editor/engines/simple.js
index 809dc58ea..7ff4c3691 100644
--- a/core/modules/editor/engines/simple.js
+++ b/core/modules/editor/engines/simple.js
@@ -68,6 +68,10 @@ function SimpleEngine(options) {
 	this.widget.domNodes.push(this.domNode);
 }
 
+SimpleEngine.prototype.assignDomNodeClasses = function() {
+	this.domNode.className = this.widget.getAttribute("class","");
+};
+
 /*
 Set the text of the engine if it doesn't currently have focus
 */