diff --git a/Source/ProofOfConcept/Program.cs b/Source/ProofOfConcept/Program.cs
index 7c6d63e..7412f40 100644
--- a/Source/ProofOfConcept/Program.cs
+++ b/Source/ProofOfConcept/Program.cs
@@ -109,6 +109,9 @@ builder.Services
         o.AdditionalAuthorizationParameters.Add("show_keypair_step", "true");
         o.AdditionalAuthorizationParameters.Add("prompt_missing_scopes", "true");
 
+        o.TokenValidationParameters.ValidateIssuer = true;
+        o.TokenValidationParameters.ValidIssuer = o.Authority;
+        
         // ✅ Add the Fleet API audience to the token POST
         const string FleetApiAudience = "https://fleet-api.prd.eu.vn.cloud.tesla.com"; // set your region base
         o.Events = new OpenIdConnectEvents