diff --git a/net/FlatBuffers/FlatBuffers.csproj b/net/FlatBuffers/FlatBuffers.csproj
index 3ae938a15..2a0cf99de 100644
--- a/net/FlatBuffers/FlatBuffers.csproj
+++ b/net/FlatBuffers/FlatBuffers.csproj
@@ -37,6 +37,7 @@
     <Compile Include="ByteBuffer.cs" />
     <Compile Include="FlatBufferBuilder.cs" />
     <Compile Include="FlatBufferConstants.cs" />
+    <Compile Include="IFlatbufferObject.cs" />
     <Compile Include="Offset.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Struct.cs" />