diff --git a/browser/base/content/browser-siteIdentity.js b/browser/base/content/browser-siteIdentity.js
index fceae6718a1a..a0987058af5f 100644
--- a/browser/base/content/browser-siteIdentity.js
+++ b/browser/base/content/browser-siteIdentity.js
@@ -1279,8 +1279,7 @@ var gIdentityHandler = {
     let urlString = value + "\n" + gBrowser.contentTitle;
     let htmlString = '<a href="' + value + '">' + value + "</a>";
 
-    let windowUtils = window.windowUtils;
-    let scale = windowUtils.screenPixelsPerCSSPixel / windowUtils.fullZoom;
+    let scale = window.devicePixelRatio;
     let canvas = document.createElementNS(
       "http://www.w3.org/1999/xhtml",
       "canvas"
diff --git a/browser/base/content/tabbrowser-tabs.js b/browser/base/content/tabbrowser-tabs.js
index 6ce1cd7f53cf..b19166f6e74c 100644
--- a/browser/base/content/tabbrowser-tabs.js
+++ b/browser/base/content/tabbrowser-tabs.js
@@ -432,8 +432,7 @@
       // Until canvas is HiDPI-aware (bug 780362), we need to scale the desired
       // canvas size (in CSS pixels) to the window's backing resolution in order
       // to get a full-resolution drag image for use on HiDPI displays.
-      let windowUtils = window.windowUtils;
-      let scale = windowUtils.screenPixelsPerCSSPixel / windowUtils.fullZoom;
+      let scale = window.devicePixelRatio;
       let canvas = this._dndCanvas;
       if (!canvas) {
         this._dndCanvas = canvas = document.createElementNS(
diff --git a/browser/components/search/SearchOneOffs.jsm b/browser/components/search/SearchOneOffs.jsm
index e6f88d58886f..5a773f979eec 100644
--- a/browser/components/search/SearchOneOffs.jsm
+++ b/browser/components/search/SearchOneOffs.jsm
@@ -474,7 +474,7 @@ class SearchOneOffs {
       // This is likely because the clientWidth getter rounds the value, but
       // the panel's border width is not an integer.
       // As a workaround, decrement the width if the scale is not an integer.
-      let scale = this.window.windowUtils.screenPixelsPerCSSPixel;
+      let scale = this.window.devicePixelRatio;
       if (Math.floor(scale) != scale) {
         --buttonsWidth;
       }
diff --git a/browser/modules/WindowsPreviewPerTab.jsm b/browser/modules/WindowsPreviewPerTab.jsm
index 0af57a89297f..6ee8a6f12533 100644
--- a/browser/modules/WindowsPreviewPerTab.jsm
+++ b/browser/modules/WindowsPreviewPerTab.jsm
@@ -202,20 +202,6 @@ PreviewController.prototype = {
     this.canvasPreview.height = aRequestedHeight;
   },
 
-  get zoom() {
-    // Note that winutils.fullZoom accounts for "quantization" of the zoom factor
-    // from nsIContentViewer due to conversion through appUnits.
-    // We do -not- want screenPixelsPerCSSPixel here, because that would -also-
-    // incorporate any scaling that is applied due to hi-dpi resolution options.
-    return this.tab.linkedBrowser.fullZoom;
-  },
-
-  get screenPixelsPerCSSPixel() {
-    let chromeWin = this.tab.ownerGlobal;
-    let windowUtils = chromeWin.windowUtils;
-    return windowUtils.screenPixelsPerCSSPixel;
-  },
-
   get browserDims() {
     return this.tab.linkedBrowser.getBoundingClientRect();
   },
@@ -295,7 +281,7 @@ PreviewController.prototype = {
       composite.mozOpaque = false;
 
       let ctx = composite.getContext("2d");
-      let scale = this.screenPixelsPerCSSPixel / this.zoom;
+      let scale = this.win.devicePixelRatio;
 
       composite.width = winWidth * scale;
       composite.height = winHeight * scale;