--- a/toolkit/components/printing/content/printUtils.js
+++ b/toolkit/components/printing/content/printUtils.js
@@ -525,16 +525,17 @@ var PrintUtils = {
       this._sourceBrowser.docShellIsActive = true;
 
       // show the toolbar after we go into print preview mode so
       // that we can initialize the toolbar with total num pages
       const XUL_NS =
         "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
       printPreviewTB = document.createElementNS(XUL_NS, "toolbar");
       printPreviewTB.setAttribute("printpreview", true);
+      printPreviewTB.setAttribute("fullscreentoolbar", true);
       printPreviewTB.id = "print-preview-toolbar";
 
       let navToolbox = this._listener.getNavToolbox();
       navToolbox.parentNode.insertBefore(printPreviewTB, navToolbox);
       printPreviewTB.initialize(ppBrowser);
 
       // copy the window close handler
       if (document.documentElement.hasAttribute("onclose"))