diff --git a/polygerrit-ui/app/elements/diff/gr-diff-highlight/gr-annotation.ts b/polygerrit-ui/app/elements/diff/gr-diff-highlight/gr-annotation.ts
index 5e81871..79e7dbc 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-highlight/gr-annotation.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-highlight/gr-annotation.ts
@@ -134,7 +134,7 @@
 
       if (node instanceof Text) {
         this._annotateText(node, offset, subLength, cssClass);
-      } else if (node instanceof HTMLElement) {
+      } else if (node instanceof Element) {
         this.annotateElement(node, offset, subLength, cssClass);
       }