--- a/toolkit/modules/PopupNotifications.jsm
+++ b/toolkit/modules/PopupNotifications.jsm
@@ -254,25 +254,31 @@ this.PopupNotifications = function Popup
         focusedElement == this.tabbrowser.selectedBrowser ||
         // Ignore focused elements inside the notification.
         getNotificationFromElement(focusedElement) == notification ||
         notification.contains(focusedElement)) {
       this._onButtonEvent(aEvent, "secondarybuttoncommand", notification);
     }
   };
 
+  let documentElement = this.window.document.documentElement;
+  let locationBarHidden = documentElement.getAttribute("chromehidden").includes("location");
+  let isFullscreen = !!this.window.document.fullscreenElement;
+
+  this.panel.setAttribute("followanchor", !locationBarHidden && !isFullscreen);
+
   // There are no anchor icons in DOM fullscreen mode, but we would
   // still like to show the popup notification. To avoid an infinite
   // loop of showing and hiding, we have to disable followanchor
   // (which hides the element without an anchor) in fullscreen.
   this.window.addEventListener("MozDOMFullscreen:Entered", () => {
     this.panel.setAttribute("followanchor", "false");
   }, true);
   this.window.addEventListener("MozDOMFullscreen:Exited", () => {
-    this.panel.setAttribute("followanchor", "true");
+    this.panel.setAttribute("followanchor", !locationBarHidden);
   }, true);
 
   this.window.addEventListener("activate", this, true);
   if (this.tabbrowser.tabContainer)
     this.tabbrowser.tabContainer.addEventListener("TabSelect", this, true);
 }
 
 PopupNotifications.prototype = {
@@ -935,16 +941,23 @@ PopupNotifications.prototype = {
 
       // If the identity icon is not available in this window, or maybe the
       // entire location bar is hidden for any reason, use the tab as the
       // anchor. We only ever show notifications for the current browser, so we
       // can just use the current tab.
       if (!anchorElement || (anchorElement.boxObject.height == 0 &&
                              anchorElement.boxObject.width == 0)) {
         anchorElement = this.tabbrowser.selectedTab;
+
+        // If we're in an entirely chromeless environment, set the anchorElement
+        // to null and let openPopup show the notification at (0,0) later.
+        if (!anchorElement || (anchorElement.boxObject.height == 0 &&
+                               anchorElement.boxObject.width == 0)) {
+          anchorElement = null;
+        }
       }
     }
 
     if (this.isPanelOpen && this._currentAnchorElement == anchorElement) {
       notificationsToShow.forEach(function(n) {
         this._fireCallback(n, NOTIFICATION_EVENT_SHOWN);
       }, this);
 
@@ -1018,17 +1031,17 @@ PopupNotifications.prototype = {
         this.panel.dispatchEvent(new this.window.CustomEvent("Shown"));
         let event = new this.window.CustomEvent("PanelUpdated",
                                                 {"detail": notificationIds});
         this.panel.dispatchEvent(event);
       };
       this._popupshownListener = this._popupshownListener.bind(this);
       target.addEventListener("popupshown", this._popupshownListener, true);
 
-      this.panel.openPopup(anchorElement, "bottomcenter topleft");
+      this.panel.openPopup(anchorElement, "bottomcenter topleft", 0, 0);
     });
   },
 
   /**
    * Updates the notification state in response to window activation or tab
    * selection changes.
    *
    * @param notifications an array of Notification instances. if null,