diff --git a/packages/babel-helper-annotate-as-pure/src/index.js b/packages/babel-helper-annotate-as-pure/src/index.js
index f04cd31212282..1f443b0b8eddc 100644
--- a/packages/babel-helper-annotate-as-pure/src/index.js
+++ b/packages/babel-helper-annotate-as-pure/src/index.js
@@ -3,7 +3,7 @@ import * as t from "@babel/types";
 const PURE_ANNOTATION = "#__PURE__";
 
 const isPureAnnotated = ({ leadingComments }) =>
-  leadingComments &&
+  !!leadingComments &&
   leadingComments.some(comment => /[@#]__PURE__/.test(comment.value));
 
 export default function annotateAsPure(pathOrNode) {