diff --git a/example/src/WebEid.AspNetCore.Example/Controllers/Api/AuthController.cs b/example/src/WebEid.AspNetCore.Example/Controllers/Api/AuthController.cs
index e208f52..bd1430d 100644
--- a/example/src/WebEid.AspNetCore.Example/Controllers/Api/AuthController.cs
+++ b/example/src/WebEid.AspNetCore.Example/Controllers/Api/AuthController.cs
@@ -55,10 +55,14 @@ public async Task<IActionResult> Login([FromBody] AuthenticateRequestDto dto)
                 await SignInUser(dto.AuthToken);
                 return Ok();
             }
-            catch (Exception ex) when (ex is InvalidOperationException or ChallengeNonceNotFoundException or ChallengeNonceExpiredException)
+            catch (Exception ex) when (ex is ChallengeNonceNotFoundException or ChallengeNonceExpiredException)
             {
                 return Unauthorized(new { error = "challenge_nonce_not_found_or_expired" });
             }
+            catch (AuthTokenException)
+            {
+                return Unauthorized(new { error = "authentication_failed" });
+            }
         }
 
         [HttpPost("logout")]