diff --git a/src/DotPulsar/Internal/PulsarClientBuilder.cs b/src/DotPulsar/Internal/PulsarClientBuilder.cs
index 35959bd..c00f1b0 100644
--- a/src/DotPulsar/Internal/PulsarClientBuilder.cs
+++ b/src/DotPulsar/Internal/PulsarClientBuilder.cs
@@ -63,7 +63,7 @@
         public IPulsarClientBuilder AuthenticateUsingToken(string token)
         {
             _commandConnect.AuthMethodName = "token";
-            _commandConnect.AuthData = Encoding.ASCII.GetBytes(token);
+            _commandConnect.AuthData = Encoding.UTF8.GetBytes(token);
             return this;
         }