diff --git a/CryptoExchange.Net/Authentication/AuthenticationProvider.cs b/CryptoExchange.Net/Authentication/AuthenticationProvider.cs
index 533475a..c2ca2e4 100644
--- a/CryptoExchange.Net/Authentication/AuthenticationProvider.cs
+++ b/CryptoExchange.Net/Authentication/AuthenticationProvider.cs
@@ -443,6 +443,16 @@ namespace CryptoExchange.Net.Authentication
             return DateTimeConverter.ConvertToMilliseconds(GetTimestamp(apiClient)).Value.ToString(CultureInfo.InvariantCulture);
         }
 
+        /// <summary>
+        /// Get millisecond timestamp as a long including the time sync offset from the api client
+        /// </summary>
+        /// <param name="apiClient"></param>
+        /// <returns></returns>
+        protected long GetMillisecondTimestampLong(RestApiClient apiClient)
+        {
+            return DateTimeConverter.ConvertToMilliseconds(GetTimestamp(apiClient)).Value;
+        }
+
         /// <summary>
         /// Return the serialized request body
         /// </summary>