diff --git a/PInvoke/DnsApi/WinDns.cs b/PInvoke/DnsApi/WinDns.cs
index e12b75d3..1b13a15a 100644
--- a/PInvoke/DnsApi/WinDns.cs
+++ b/PInvoke/DnsApi/WinDns.cs
@@ -296,6 +296,7 @@ namespace Vanara.PInvoke
 
 		/// <summary>A value representing the query options.</summary>
 		[PInvokeData("windns.h")]
+		[Flags]
 		public enum DNS_QUERY_OPTIONS : ulong
 		{
 			/// <summary/>
@@ -3180,4 +3181,4 @@ namespace Vanara.PInvoke
 			}
 		}
 	}
-}
\ No newline at end of file
+}