diff --git a/csharp/src/Google.Protobuf/FieldCodec.cs b/csharp/src/Google.Protobuf/FieldCodec.cs
index 54cbc20..6ee8e2f 100644
--- a/csharp/src/Google.Protobuf/FieldCodec.cs
+++ b/csharp/src/Google.Protobuf/FieldCodec.cs
@@ -264,15 +264,15 @@
         {
             private static readonly Dictionary<System.Type, object> Codecs = new Dictionary<System.Type, object>
             {
-                { typeof(bool), ForBool(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
-                { typeof(int), ForInt32(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
-                { typeof(long), ForInt64(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
-                { typeof(uint), ForUInt32(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
-                { typeof(ulong), ForUInt64(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
-                { typeof(float), ForFloat(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Fixed32)) },
-                { typeof(double), ForDouble(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.Fixed64)) },
-                { typeof(string), ForString(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.LengthDelimited)) },
-                { typeof(ByteString), ForBytes(WireFormat.MakeTag(Wrappers.WrapperValueFieldNumber, WireFormat.WireType.LengthDelimited)) }
+                { typeof(bool), ForBool(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
+                { typeof(int), ForInt32(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
+                { typeof(long), ForInt64(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
+                { typeof(uint), ForUInt32(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
+                { typeof(ulong), ForUInt64(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) },
+                { typeof(float), ForFloat(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Fixed32)) },
+                { typeof(double), ForDouble(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Fixed64)) },
+                { typeof(string), ForString(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.LengthDelimited)) },
+                { typeof(ByteString), ForBytes(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.LengthDelimited)) }
             };
 
             /// <summary>