diff --git a/src/Microsoft.ML.Core/Properties/AssemblyInfo.cs b/src/Microsoft.ML.Core/Properties/AssemblyInfo.cs
index 7b8699ceb0..e08d9685c4 100644
--- a/src/Microsoft.ML.Core/Properties/AssemblyInfo.cs
+++ b/src/Microsoft.ML.Core/Properties/AssemblyInfo.cs
@@ -5,6 +5,7 @@
 using System.Runtime.CompilerServices;
 using Microsoft.ML;
 
+// Test assemblies that require access to internal APIs.
 [assembly: InternalsVisibleTo(assemblyName: "Microsoft.Data.Analysis.Tests" + PublicKey.Value)]
 [assembly: InternalsVisibleTo(assemblyName: "Microsoft.ML.TestFramework" + PublicKey.Value)]
 [assembly: InternalsVisibleTo(assemblyName: "Microsoft.ML.TestFrameworkCommon" + PublicKey.Value)]