diff --git a/src/WysiwygTrait.php b/src/WysiwygTrait.php
index ea3b61fd..daf64604 100644
--- a/src/WysiwygTrait.php
+++ b/src/WysiwygTrait.php
@@ -34,7 +34,7 @@ public function wysiwygFillField(string $field, string $value): void {
 
     $driver = $this->getSession()->getDriver();
     try {
-      $driver->evaluateScript(TRUE);
+      $driver->evaluateScript('true');
     }
     catch (UnsupportedDriverActionException $exception) {
       // For non-JS drivers process field in a standard way.