diff --git a/CryptoExchange.Net/ExtensionMethods.cs b/CryptoExchange.Net/ExtensionMethods.cs
index 3c9d356..0545633 100644
--- a/CryptoExchange.Net/ExtensionMethods.cs
+++ b/CryptoExchange.Net/ExtensionMethods.cs
@@ -455,6 +455,7 @@ namespace CryptoExchange.Net
             var uriBuilder = new UriBuilder();
             uriBuilder.Scheme = baseUri.Scheme;
             uriBuilder.Host = baseUri.Host;
+            uriBuilder.Port = baseUri.Port;
             uriBuilder.Path = baseUri.AbsolutePath;
             var httpValueCollection = HttpUtility.ParseQueryString(string.Empty);
             foreach (var parameter in parameters)