diff --git a/RaceLapTimer/Interfaces/Interfaces.csproj b/RaceLapTimer/Interfaces/Interfaces.csproj
index 2ff5ad6..b3909c5 100644
--- a/RaceLapTimer/Interfaces/Interfaces.csproj
+++ b/RaceLapTimer/Interfaces/Interfaces.csproj
@@ -50,6 +50,9 @@
     <Compile Include="INotifierManager.cs" />
     <Compile Include="INotifierProvider.cs" />
     <Compile Include="INotifierProviderFactory.cs" />
+    <Compile Include="ISystemControl.cs" />
+    <Compile Include="ISystemControlProviderFactory.cs" />
+    <Compile Include="ITransponderUtilities.cs" />
     <Compile Include="NotificationEventArgs.cs" />
     <Compile Include="Pilot.cs" />
     <Compile Include="RaceSession.cs" />