regenerate C# protos
diff --git a/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs b/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs
index 706b7c4..c1f43ce 100644
--- a/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs
+++ b/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs
@@ -2,7 +2,7 @@
 //     Generated by the protocol buffer compiler.  DO NOT EDIT!
 //     source: unittest.proto
 // </auto-generated>
-#pragma warning disable 1591, 0612, 3021
+#pragma warning disable 1591, 0612, 3021, 8981
 #region Designer generated code
 
 using pb = global::Google.Protobuf;