diff --git a/src/Authress.SDK/Client/AuthressClientTokenProvider.cs b/src/Authress.SDK/Client/AuthressClientTokenProvider.cs
index be0f091..76cfd77 100644
--- a/src/Authress.SDK/Client/AuthressClientTokenProvider.cs
+++ b/src/Authress.SDK/Client/AuthressClientTokenProvider.cs
@@ -145,6 +145,7 @@ public Task<string> GetBearerToken(string authressCustomDomainFallback = null)
             {
                 { "iss", GetIssuer(authressCustomDomainFallback) },
                 { "sub", accessKey.ClientId },
+                { "client_id", accessKey.ClientId },
                 { "exp", (int)Math.Floor(expiryDate.Subtract(new DateTime(1970,1,1,0,0,0, DateTimeKind.Utc)).TotalSeconds) },
                 { "iat", (int)Math.Floor(now.Subtract(new DateTime(1970,1,1,0,0,0, DateTimeKind.Utc)).TotalSeconds) },
                 { "nbf", (int)Math.Floor(now.Subtract(TimeSpan.FromMinutes(10)).Subtract(new DateTime(1970,1,1,0,0,0, DateTimeKind.Utc)).TotalSeconds) },