diff --git a/browser/modules/PluginContent.jsm b/browser/modules/PluginContent.jsm
index 9dcb266a3442..678369d7e3ec 100644
--- a/browser/modules/PluginContent.jsm
+++ b/browser/modules/PluginContent.jsm
@@ -175,7 +175,7 @@ PluginContent.prototype = {
   },
 
   _getPluginInfo(pluginElement) {
-    if (ChromeUtils.getClassName(pluginElement) === "HTMLAnchorElement") {
+    if (pluginElement instanceof Ci.nsIDOMHTMLAnchorElement) {
       // Anchor elements are our place holders, and we only have them for Flash
       let pluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
       return {
@@ -649,7 +649,7 @@ PluginContent.prototype = {
     let doc = plugin.ownerDocument;
     let pluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
     let permissionString;
-    if (ChromeUtils.getClassName(plugin) === "HTMLAnchorElement") {
+    if (plugin instanceof Ci.nsIDOMHTMLAnchorElement) {
       // We only have replacement content for Flash installs
       permissionString = pluginHost.getPermissionStringForType(FLASH_MIME_TYPE);
     } else {
@@ -684,7 +684,7 @@ PluginContent.prototype = {
     let contentWindow = plugin.ownerGlobal.top;
     let overlay = this.getPluginUI(plugin, "main");
     // Have to check that the target is not the link to update the plugin
-    if (!(ChromeUtils.getClassName(event.originalTarget) === "HTMLAnchorElement") &&
+    if (!(event.originalTarget instanceof contentWindow.HTMLAnchorElement) &&
         (event.originalTarget.getAttribute("anonid") != "closeIcon") &&
         !overlay.hasAttribute("dismissed") &&
         event.button == 0 &&
@@ -730,7 +730,7 @@ PluginContent.prototype = {
       }
       if (pluginInfo.permissionString == pluginHost.getPermissionStringForType(plugin.actualType)) {
         let overlay = this.getPluginUI(plugin, "main");
-        if (ChromeUtils.getClassName(plugin) === "HTMLAnchorElement") {
+        if (plugin instanceof Ci.nsIDOMHTMLAnchorElement) {
           placeHolderFound = true;
         } else {
           pluginFound = true;
diff --git a/dom/browser-element/BrowserElementChildPreload.js b/dom/browser-element/BrowserElementChildPreload.js
index 5c24b2b5827c..fc796ea71535 100644
--- a/dom/browser-element/BrowserElementChildPreload.js
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -666,7 +666,7 @@ BrowserElementChild.prototype = {
   _ClickHandler: function(e) {
 
     let isHTMLLink = node =>
-      ((ChromeUtils.getClassName(node) === "HTMLAnchorElement" && node.href) ||
+      ((node instanceof Ci.nsIDOMHTMLAnchorElement && node.href) ||
        (node instanceof Ci.nsIDOMHTMLAreaElement && node.href) ||
         node instanceof Ci.nsIDOMHTMLLinkElement);
 
@@ -855,7 +855,7 @@ BrowserElementChild.prototype = {
   _getSystemCtxMenuData: function(elem) {
     let documentURI =
       docShell.QueryInterface(Ci.nsIWebNavigation).currentURI.spec;
-    if ((ChromeUtils.getClassName(elem) === "HTMLAnchorElement" && elem.href) ||
+    if ((elem instanceof Ci.nsIDOMHTMLAnchorElement && elem.href) ||
         (elem instanceof Ci.nsIDOMHTMLAreaElement && elem.href)) {
       return {uri: elem.href,
               documentURI: documentURI,
diff --git a/dom/ipc/remote-test.js b/dom/ipc/remote-test.js
index 58e2e74b2b95..dd21415cd740 100644
--- a/dom/ipc/remote-test.js
+++ b/dom/ipc/remote-test.js
@@ -26,7 +26,7 @@ var dshell = content.QueryInterface(Ci.nsIInterfaceRequestor)
 addEventListener("click",
   function(e) {
     dump(e.target + "\n");
-    if (ChromeUtils.getClassName(e.target) === "HTMLAnchorElement" &&
+    if (e.target instanceof Components.interfaces.nsIDOMHTMLAnchorElement &&
         dshell == docShell) {
       var retval = docShell.QueryInterface(Components.interfaces.nsIInterfaceRequestor).
                             getInterface(Components.interfaces.nsIContentFrameMessageManager).
diff --git a/mobile/android/chrome/content/browser.js b/mobile/android/chrome/content/browser.js
index 09956f92cc4c..db27d2da945a 100644
--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -2735,7 +2735,7 @@ var NativeWindow = {
      */
     _getContextType: function(element) {
       // For anchor nodes, we try to use the scheme to pick a string
-      if (ChromeUtils.getClassName(element) === "HTMLAnchorElement") {
+      if (element instanceof Ci.nsIDOMHTMLAnchorElement) {
         let uri = this.makeURI(this._getLinkURL(element));
         try {
           return Strings.browser.GetStringFromName("browser.menu.context." + uri.scheme);
@@ -2820,7 +2820,7 @@ var NativeWindow = {
 
     // Returns a url associated with a node
     _getUrl: function(node) {
-      if ((ChromeUtils.getClassName(node) === "HTMLAnchorElement" && node.href) ||
+      if ((node instanceof Ci.nsIDOMHTMLAnchorElement && node.href) ||
           (node instanceof Ci.nsIDOMHTMLAreaElement && node.href)) {
         return this._getLinkURL(node);
       } else if (node instanceof Ci.nsIImageLoadingContent && node.currentURI) {
@@ -3051,7 +3051,7 @@ var NativeWindow = {
 
     _getLink: function(aElement) {
       if (aElement.nodeType == Ci.nsIDOMNode.ELEMENT_NODE &&
-          ((ChromeUtils.getClassName(aElement) === "HTMLAnchorElement" && aElement.href) ||
+          ((aElement instanceof Ci.nsIDOMHTMLAnchorElement && aElement.href) ||
           (aElement instanceof Ci.nsIDOMHTMLAreaElement && aElement.href) ||
           aElement instanceof Ci.nsIDOMHTMLLinkElement ||
           aElement.getAttributeNS(kXLinkNamespace, "type") == "simple")) {
@@ -4775,7 +4775,7 @@ var BrowserEventHandler = {
 
   _getLinkURI: function(aElement) {
     if (aElement.nodeType == Ci.nsIDOMNode.ELEMENT_NODE &&
-        ((ChromeUtils.getClassName(aElement) === "HTMLAnchorElement" && aElement.href) ||
+        ((aElement instanceof Ci.nsIDOMHTMLAnchorElement && aElement.href) ||
         (aElement instanceof Ci.nsIDOMHTMLAreaElement && aElement.href))) {
       try {
         return Services.io.newURI(aElement.href);