diff --git a/CoinGecko.Net/Objects/Models/CoinGeckoMarket.cs b/CoinGecko.Net/Objects/Models/CoinGeckoMarket.cs
index 6d732d8..7c0cca8 100644
--- a/CoinGecko.Net/Objects/Models/CoinGeckoMarket.cs
+++ b/CoinGecko.Net/Objects/Models/CoinGeckoMarket.cs
@@ -114,7 +114,7 @@ public record CoinGeckoMarket
         /// </summary>
         [JsonConverter(typeof(DateTimeConverter))]
         [JsonPropertyName("ath_date")]
-        public DateTime AllTimeHighTimestamp { get; set; }
+        public DateTime? AllTimeHighTimestamp { get; set; }
         /// <summary>
         /// All time low price
         /// </summary>
@@ -141,7 +141,7 @@ public record CoinGeckoMarket
         /// </summary>
         [JsonConverter(typeof(DateTimeConverter))]
         [JsonPropertyName("last_updated")]
-        public DateTime LastUpdated { get; set; }
+        public DateTime? LastUpdated { get; set; }
     }
 
     /// <summary>