diff --git a/Assets/UdonSharp/Editor/UdonSharpCompiler.cs b/Assets/UdonSharp/Editor/UdonSharpCompiler.cs
index 816c0cad..f99cf3d4 100644
--- a/Assets/UdonSharp/Editor/UdonSharpCompiler.cs
+++ b/Assets/UdonSharp/Editor/UdonSharpCompiler.cs
@@ -29,7 +29,7 @@ public UdonSharpCompiler(UdonSharpProgramAsset programAsset)
 
         public UdonSharpCompiler(UdonSharpProgramAsset[] programAssets)
         {
-            modules = programAssets.Select(e => new CompilationModule(e)).ToArray();
+            modules = programAssets.Where(e => e.sourceCsScript != null).Select(e => new CompilationModule(e)).ToArray();
         }
 
         public void Compile()