diff --git a/Src/Notion.Client/Models/PropertyValue/NumberPropertyValue.cs b/Src/Notion.Client/Models/PropertyValue/NumberPropertyValue.cs
index 863d5f1b..a98a34d4 100644
--- a/Src/Notion.Client/Models/PropertyValue/NumberPropertyValue.cs
+++ b/Src/Notion.Client/Models/PropertyValue/NumberPropertyValue.cs
@@ -13,6 +13,6 @@ public class NumberPropertyValue : PropertyValue
         /// Value of number
         /// </summary>
         [JsonProperty("number")]
-        public double Number { get; set; }
+        public double? Number { get; set; }
     }
 }
diff --git a/Src/Notion.Client/Models/PropertyValue/RollupPropertyValue.cs b/Src/Notion.Client/Models/PropertyValue/RollupPropertyValue.cs
index c6587226..7c573081 100644
--- a/Src/Notion.Client/Models/PropertyValue/RollupPropertyValue.cs
+++ b/Src/Notion.Client/Models/PropertyValue/RollupPropertyValue.cs
@@ -29,7 +29,7 @@ public class RollupValue
         /// Number rollup property values contain a number
         /// </summary>
         [JsonProperty("number")]
-        public double Number { get; set; }
+        public double? Number { get; set; }
 
         /// <summary>
         /// Date rollup property values contain a date property value.