diff --git a/js/ui/BUILD.bazel b/js/ui/BUILD.bazel
index 454ce54..d5fec71 100644
--- a/js/ui/BUILD.bazel
+++ b/js/ui/BUILD.bazel
@@ -12,6 +12,7 @@ closure_js_library(
         ":injector",
         ":keyboard",
         "@com_google_javascript_closure_library//closure/goog/asserts",
+        "@com_google_javascript_closure_library//closure/goog/asserts:dom",
         "@com_google_javascript_closure_library//closure/goog/dom",
         "@com_google_javascript_closure_library//closure/goog/events",
         "@com_google_javascript_closure_library//closure/goog/events:eventhandler",
@@ -37,7 +38,7 @@ closure_js_library(
         "history/event.js",
     ],
     deps = [
-        "@com_google_javascript_closure_library//closure/goog/asserts",
+        "@com_google_javascript_closure_library//closure/goog/asserts:dom",
         "@com_google_javascript_closure_library//closure/goog/dom",
         "@com_google_javascript_closure_library//closure/goog/dom:tagname",
         "@com_google_javascript_closure_library//closure/goog/events",
@@ -124,6 +125,7 @@ closure_js_library(
     deps = [
         ":core",
         "@com_google_javascript_closure_library//closure/goog/asserts",
+        "@com_google_javascript_closure_library//closure/goog/asserts:dom",
         "@com_google_javascript_closure_library//closure/goog/dom",
     ],
 )
diff --git a/js/ui/component.js b/js/ui/component.js
index b84aaa4..18ffef4 100644
--- a/js/ui/component.js
+++ b/js/ui/component.js
@@ -7,8 +7,8 @@ const BgColorTransform = goog.require('goog.fx.dom.BgColorTransform');
 const ComponentEventType = goog.require('goog.ui.Component.EventType');
 const GoogUiComponent = goog.require('goog.ui.Component');
 const GoogUiControl = goog.require('goog.ui.Control');
-// const Route = goog.require('stack.ui.Route');
 const asserts = goog.require('goog.asserts');
+const assertsDom = goog.require('goog.asserts.dom');
 const easing = goog.require('goog.fx.easing');
 const strings = goog.require('goog.string');
 const style = goog.require('goog.style');
@@ -275,7 +275,7 @@ class Component extends GoogUiComponent {
     var end = opt_end || [256, 256, 256];
     var time = opt_time || 250;
     var accel = opt_accel || easing.easeOutLong;
-    var element = opt_element || asserts.assertElement(this.getContentElement());
+    var element = opt_element || assertsDom.assertIsElement(this.getContentElement());
 
     fx = this.fx_ =
       new BgColorTransform(element, start, end, time, accel);
diff --git a/js/ui/core.js b/js/ui/core.js
index 15b15fe..5cbea59 100644
--- a/js/ui/core.js
+++ b/js/ui/core.js
@@ -17,6 +17,7 @@ const Injector = goog.require('stack.ui.Injector');
 const Keyboard = goog.require('stack.ui.Keyboard');
 const Resolver = goog.require('goog.promise.Resolver');
 const asserts = goog.require('goog.asserts');
+const assertsDom = goog.require('goog.asserts.dom');
 const dom = goog.require('goog.dom');
 const easing = goog.require('goog.fx.easing');
 const events = goog.require('goog.events');
@@ -683,7 +684,7 @@ class Component extends GoogUiComponent {
         var end = opt_end || [256, 256, 256];
         var time = opt_time || 250;
         var accel = opt_accel || easing.easeOutLong;
-        var element = opt_element || asserts.assertElement(this.getContentElement());
+        var element = opt_element || assertsDom.assertIsElement(this.getContentElement());
 
         fx = this.fx_ =
             new BgColorTransform(element, start, end, time, accel);
diff --git a/js/ui/history.js b/js/ui/history.js
index 7c06f46..61d525e 100644
--- a/js/ui/history.js
+++ b/js/ui/history.js
@@ -10,7 +10,7 @@ const HistoryEvent = goog.require('goog.history.Event');
 const HistoryEventType = goog.require('goog.history.EventType');
 const Html5History = goog.require('goog.history.Html5History');
 const TagName = goog.require('goog.dom.TagName');
-const asserts = goog.require('goog.asserts');
+const assertsDom = goog.require('goog.asserts.dom');
 const dom = goog.require('goog.dom');
 const events = goog.require('goog.events');
 const strings = goog.require('goog.string');
@@ -54,7 +54,7 @@ class History extends EventTarget {
     // Element that was clicked could be a child of of the <a>, so
     // look up through the ancestry chain.
     let anchor = /** @type {?HTMLAnchorElement} */ (
-      dom.getAncestor(asserts.assertElement(e.target),
+      dom.getAncestor(assertsDom.assertIsElement(e.target),
         el => el instanceof HTMLElement && el.tagName === TagName.A.toString(),
         true)
     );
diff --git a/js/ui/syntax.js b/js/ui/syntax.js
index 9f60f1b..15feb5b 100644
--- a/js/ui/syntax.js
+++ b/js/ui/syntax.js
@@ -4,6 +4,7 @@
 goog.module('stack.ui.Syntax');
 
 const asserts = goog.require('goog.asserts');
+const assertsDom = goog.require('goog.asserts.dom');
 const dom = goog.require('goog.dom');
 const { Component } = goog.require('stack.ui');
 
@@ -43,7 +44,7 @@ class Syntax extends Component {
    */
   getCodeElement() {
     return /** @type{!HTMLSpanElement} */(
-      asserts.assertElement(
+      assertsDom.assertIsElement(
         /** @type{!HTMLElement} */(
           this.getElementStrict()
         ).firstElementChild