diff --git a/Src/Asp.NetCore2/SqlSugar/Utilities/ValidateExtensions.cs b/Src/Asp.NetCore2/SqlSugar/Utilities/ValidateExtensions.cs
index 9bdf780fc..975f0aa97 100644
--- a/Src/Asp.NetCore2/SqlSugar/Utilities/ValidateExtensions.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Utilities/ValidateExtensions.cs
@@ -155,6 +155,10 @@ namespace SqlSugar
         }
         public static bool IsIterator(this Type type)
         {
+            if (type.BaseType == null)
+            {
+                return false;
+            }
             if (type.BaseType.IsGenericType)
             {
                 return type.BaseType?.GetGenericTypeDefinition()?.FullName == "System.Linq.Enumerable+Iterator`1";