diff --git a/lib/rules/no-unknown-property.js b/lib/rules/no-unknown-property.js
index 24e8e54513..cc881a8a3b 100644
--- a/lib/rules/no-unknown-property.js
+++ b/lib/rules/no-unknown-property.js
@@ -174,7 +174,7 @@ function getTagName(node) {
  * @returns {Boolean} result
  */
 function tagNameHasDot(node) {
-  return Boolean(
+  return !!(
     node.parent &&
     node.parent.name &&
     node.parent.name.type === 'JSXMemberExpression'