diff --git a/CapnpC.CSharp.Generator/CodeGen/SkeletonWorder.cs b/CapnpC.CSharp.Generator/CodeGen/SkeletonWorder.cs
index 703ee3b..6887804 100644
--- a/CapnpC.CSharp.Generator/CodeGen/SkeletonWorder.cs
+++ b/CapnpC.CSharp.Generator/CodeGen/SkeletonWorder.cs
@@ -2,10 +2,8 @@
 
 namespace CapnpC.CSharp.Generator.CodeGen
 {
-    class SkeletonWorder : Capnp.Rpc.Skeleton<object>
+    abstract class SkeletonWorder : Capnp.Rpc.Skeleton<object>
     {
-        public override ulong InterfaceId => throw new NotImplementedException();
-
         public const string SetMethodTableName = nameof(SkeletonWorder.SetMethodTable);
         public const string ImplName = nameof(SkeletonWorder.Impl);
     }
diff --git a/scripts/measure-coverage.ps1 b/scripts/measure-coverage.ps1
index 8b9f809..0f3fa03 100644
--- a/scripts/measure-coverage.ps1
+++ b/scripts/measure-coverage.ps1
@@ -40,7 +40,7 @@ If(!(test-path $coverageReportDir))
 
 & $openCover -target:"$vsTestConsole" `
   -targetArgs:"/inIsolation $generatorTests" `
-  -filter:"+[CapnpC.CSharp.Generator]*" `
+  -filter:"+[CapnpC.CSharp.Generator]CapnpC.CSharp.Generator.* -[CapnpC.CSharp.Generator]CapnpC.CSharp.Generator.Schema.*" `
   -excludebyattribute:"System.CodeDom.Compiler.GeneratedCodeAttribute" `
   -output:"$coverageOutputGenerator" `
   -mergebyhash -register:user -oldStyle