1 files changed, 2 insertions, 2 deletions
diff --git a/csharp/src/Google.Protobuf/Reflection/MapFieldAccessor.cs b/csharp/src/Google.Protobuf/Reflection/MapFieldAccessor.cs
index 6df4c5f0..9ed7f8c4 100644
--- a/csharp/src/Google.Protobuf/Reflection/MapFieldAccessor.cs
+++ b/csharp/src/Google.Protobuf/Reflection/MapFieldAccessor.cs
@@ -45,13 +45,13 @@ namespace Google.Protobuf.Reflection
         {
         }
 
-        public override void Clear(object message)
+        public override void Clear(IMessage message)
         {
             IDictionary list = (IDictionary) GetValue(message);
             list.Clear();
         }
 
-        public override void SetValue(object message, object value)
+        public override void SetValue(IMessage message, object value)
         {
             throw new InvalidOperationException("SetValue is not implemented for map fields");
         }