diff --git a/lib/utils/mixin.html b/lib/utils/mixin.html
index 070ea03261..525d1bc209 100644
--- a/lib/utils/mixin.html
+++ b/lib/utils/mixin.html
@@ -32,7 +32,7 @@
   /* eslint-disable valid-jsdoc */
   /**
    * Wraps an ES6 class expression mixin such that the mixin is only applied
-   * if it has not already been applied its base argument.  Also memoizes mixin
+   * if it has not already been applied its base argument. Also memoizes mixin
    * applications.
    *
    * @memberof Polymer