diff --git a/src/Whip_MessageDismisser.php b/src/Whip_MessageDismisser.php
index 8759b3d..ee9a9d5 100644
--- a/src/Whip_MessageDismisser.php
+++ b/src/Whip_MessageDismisser.php
@@ -71,6 +71,6 @@ public function isDismissed() {
 	 * @return bool True when the nonce is valid.
 	 */
 	public function verifyNonce( $nonce, $action ) {
-		return wp_verify_nonce( $nonce, $action );
+		return (bool) wp_verify_nonce( $nonce, $action );
 	}
 }