diff --git a/lib/legacy/class.html b/lib/legacy/class.html
index f52f042c09..0ceb6471dd 100644
--- a/lib/legacy/class.html
+++ b/lib/legacy/class.html
@@ -44,7 +44,7 @@
       if (!behaviors) {
         return /** @type {HTMLElement} */(klass);
       }
-      // NOTE: ensure the bahevior is extending a class with
+      // NOTE: ensure the behavior is extending a class with
       // legacy element api. This is necessary since behaviors expect to be able
       // to access 1.x legacy api.
       klass = Polymer.LegacyElementMixin(klass);