diff --git a/src/RippleAddressCodec.php b/src/RippleAddressCodec.php
index 9c7db66..6ff11a4 100644
--- a/src/RippleAddressCodec.php
+++ b/src/RippleAddressCodec.php
@@ -115,7 +115,7 @@ public function classicAddressToXAddress(string $classicAddress, $tag, bool $tes
 
     public function encodeXAddress(Buffer $accountId, $tag, bool $test = false): string
     {
-        $flag = $tag === false ? 0 : $tag <= MAX_32_BIT_UNSIGNED_INT ? 1 : 2;
+        $flag = $tag === false ? 0 : ($tag <= MAX_32_BIT_UNSIGNED_INT ? 1 : 2);
         if ($flag === 2)
         {
             throw new Exception('Invalid tag');