diff --git a/src/ExtensionSet.php b/src/ExtensionSet.php
index abca18f14..04392b2e6 100644
--- a/src/ExtensionSet.php
+++ b/src/ExtensionSet.php
@@ -510,7 +510,7 @@ final class ExtensionSet
             if ($op['callable']) {
                 $expressionParsers[] = $this->convertInfixExpressionParser($op['class'], $operator, $op['precedence'], $op['associativity'], $op['precedence_change'] ?? null, $op['aliases'] ?? [], $op['callable']);
             } else {
-                $expressionParsers[] = new BinaryOperatorExpressionParser($op['class'], $operator, $op['precedence'], $op['associativity'], $op['precedence_change'] ?? null, $op['aliases'] ?? []);
+                $expressionParsers[] = new BinaryOperatorExpressionParser($op['class'], $operator, $op['precedence'], $op['associativity'], $op['precedence_change'] ?? null, '', $op['aliases'] ?? []);
             }
         }