diff --git a/lib/csharp/src/Protocol/TProtocolException.cs b/lib/csharp/src/Protocol/TProtocolException.cs
index c0f007e..b81db1a 100644
--- a/lib/csharp/src/Protocol/TProtocolException.cs
+++ b/lib/csharp/src/Protocol/TProtocolException.cs
@@ -42,8 +42,8 @@
         {
         }
 
-        public TProtocolException(int type)
-            : base()
+        public TProtocolException(int type, Exception inner = null)
+            : base(inner)
         {
             type_ = type;
         }