--- a/devtools/client/webconsole/webconsole.js
+++ b/devtools/client/webconsole/webconsole.js
@@ -632,17 +632,22 @@ WebConsoleFrame.prototype = {
   },
 
   /**
    * Resizes the output node to fit the output wrapped.
    * We need this because it makes the layout a lot faster than
    * using -moz-box-flex and 100% width.  See Bug 1237368.
    */
   resize: function () {
-    this.outputNode.style.width = this.outputWrapper.clientWidth + "px";
+    if (this.NEW_CONSOLE_OUTPUT_ENABLED) {
+      this.experimentalOutputNode.style.width =
+        this.outputWrapper.clientWidth + "px";
+    } else {
+      this.outputNode.style.width = this.outputWrapper.clientWidth + "px";
+    }
   },
 
   /**
    * Sets the focus to JavaScript input field when the web console tab is
    * selected or when there is a split console present.
    * @private
    */
   _onPanelSelected: function () {