--- a/devtools/client/debugger/new/panel.js
+++ b/devtools/client/debugger/new/panel.js
@@ -9,17 +9,17 @@ function DebuggerPanel(iframeWindow, too
 }
 
 DebuggerPanel.prototype = {
   open: function() {
     let targetPromise;
     if (!this.toolbox.target.isRemote) {
       targetPromise = this.toolbox.target.makeRemote();
     } else {
-      targetPromise = promise.resolve(this.toolbox.target);
+      targetPromise = Promise.resolve(this.toolbox.target);
     }
 
     return targetPromise.then(() => {
       this.panelWin.Debugger.bootstrap({
         threadClient: this.toolbox.threadClient,
         tabTarget: this.toolbox.target
       });
       return this;