diff --git a/polygerrit-ui/app/elements/gr-app.html b/polygerrit-ui/app/elements/gr-app.html
index e7bd965..758add8 100644
--- a/polygerrit-ui/app/elements/gr-app.html
+++ b/polygerrit-ui/app/elements/gr-app.html
@@ -26,6 +26,9 @@
       passiveTouchGestures: true,
     };
   }
+  // Needed for JSCompiler to understand it's global.
+  // eslint-disable-next-line no-unused-vars, prefer-const
+  let Gerrit = window.Gerrit || {};
 </script>
 
 <link rel="import" href="../bower_components/polymer/polymer.html">
diff --git a/polygerrit-ui/app/embed/embed.html b/polygerrit-ui/app/embed/embed.html
index 9fb5c23..647f602 100644
--- a/polygerrit-ui/app/embed/embed.html
+++ b/polygerrit-ui/app/embed/embed.html
@@ -14,6 +14,11 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
+<script>
+  // Needed for JSCompiler to understand it's global.
+  // eslint-disable-next-line no-unused-vars, prefer-const
+  let Gerrit = window.Gerrit || {};
+</script>
 <link rel="import" href="../bower_components/polymer/polymer.html">
 <link rel="import" href="../elements/change/gr-change-view/gr-change-view.html">
 <link rel="import" href="../elements/core/gr-search-bar/gr-search-bar.html">
diff --git a/polygerrit-ui/app/gr-diff/gr-diff-root.html b/polygerrit-ui/app/gr-diff/gr-diff-root.html
new file mode 100644
index 0000000..557f48b
--- /dev/null
+++ b/polygerrit-ui/app/gr-diff/gr-diff-root.html
@@ -0,0 +1,6 @@
+<script>
+  // Needed for JSCompiler to understand it's global.
+  // eslint-disable-next-line no-unused-vars, prefer-const
+  let Gerrit = window.Gerrit || {};
+</script>
+<link rel="import" href="../elements/diff/gr-diff/gr-diff.html">
\ No newline at end of file