diff --git a/src/Support/Builder.php b/src/Support/Builder.php
index 0c57cb1..6c2c9a3 100644
--- a/src/Support/Builder.php
+++ b/src/Support/Builder.php
@@ -209,8 +209,7 @@ protected function invalidOperatorAndValue($operator, $value)
      */
     protected function invalidOperator($operator)
     {
-        return ! in_array(strtolower($operator), $this->operators, true) &&
-               ! in_array(strtolower($operator), $this->grammar->getOperators(), true);
+        return ! in_array(strtolower($operator), $this->operators, true);
     }
 
      /**