diff --git a/src/Infrastructure/HttpUserContext/IUserContext.cs b/src/Infrastructure/HttpUserContext/IUserContext.cs
index 18d52c9..784f907 100644
--- a/src/Infrastructure/HttpUserContext/IUserContext.cs
+++ b/src/Infrastructure/HttpUserContext/IUserContext.cs
@@ -57,7 +57,7 @@ public interface IUserContext<TId> where TId : IEquatable<TId>
     /// <param name="schemeName"></param>
     /// <returns></returns>
     JwtTokenInfo GenerateTokenInfo(IList<Claim>? claims = null,
-        double? duration = null,
+        double duration = 0,
         string schemeName = JwtBearerDefaults.AuthenticationScheme);
 
     /// <summary>
diff --git a/src/Infrastructure/HttpUserContext/UserContext.cs b/src/Infrastructure/HttpUserContext/UserContext.cs
index 38d06c7..b9ecb70 100644
--- a/src/Infrastructure/HttpUserContext/UserContext.cs
+++ b/src/Infrastructure/HttpUserContext/UserContext.cs
@@ -91,11 +91,11 @@ public class UserContext<TId>(
 
     public JwtTokenInfo GenerateTokenInfo(
         IList<Claim>? claims = null,
-        double? duration = null,
+        double duration = 0,
         string schemeName = JwtBearerDefaults.AuthenticationScheme)
     {
         claims ??= GetClaimsFromUserContext();
-        if (double.NaN == duration)
+        if (0 == duration)
         {
             duration = jwtContext.Duration;
         }
@@ -106,12 +106,12 @@ public class UserContext<TId>(
             Audience = jwtContext.Audience,
             Claims = claims?.ToDictionary(c => c.Type, c => (object)c.Value),
             NotBefore = DateTime.Now,
-            Expires = DateTime.Now.AddSeconds(duration.Value),
+            Expires = DateTime.Now.AddSeconds(duration),
             SigningCredentials = jwtContext.SigningCredentials,
         };
         var token = jsonWebTokenHandler.CreateToken(tokenDescriptor);
         token = encryptionService.Encrypt(token);
-        return new JwtTokenInfo(token, duration.Value, schemeName);
+        return new JwtTokenInfo(token, duration, schemeName);
     }
 
     public IList<Claim>? GetClaimsFromUserContext(bool includePermissions = false)