diff --git a/src/Compilers/Core/MSBuildTask/AssemblyResolution.cs b/src/Compilers/Core/MSBuildTask/AssemblyResolution.cs
index 80c03cb455a931f8641ac8cd24710fe34d5729a3..88a011d4a80bf5e63a6b819504b5e04483f5602e 100644
--- a/src/Compilers/Core/MSBuildTask/AssemblyResolution.cs
+++ b/src/Compilers/Core/MSBuildTask/AssemblyResolution.cs
@@ -54,6 +54,7 @@ private static bool TryRedirect(AssemblyName name)
                     return TryRedirect(name, s_b03f5f7f11d50a3a, 4, 0, 2, 0);
 
                 case "System.Diagnostics.StackTrace":
+                case "System.Security.AccessControl":
                     return TryRedirect(name, s_b03f5f7f11d50a3a, 4, 0, 3, 0);
 
             }
diff --git a/src/Compilers/Core/MSBuildTask/ValidateBootstrap.cs b/src/Compilers/Core/MSBuildTask/ValidateBootstrap.cs
index 37a3e71e0388173015b734dae9a34456fb7ebfba..ead4e9a0b3f2f4292fba60261b663535120554df 100644
--- a/src/Compilers/Core/MSBuildTask/ValidateBootstrap.cs
+++ b/src/Compilers/Core/MSBuildTask/ValidateBootstrap.cs
@@ -92,9 +92,16 @@ private static string NormalizePath(string path)
 
         internal static void AddFailedLoad(AssemblyName name)
         {
-            if (Path.GetExtension(name.Name) != ".resources")
+            switch (name.Name)
             {
-                s_failedLoadSet.TryAdd(name, 0);
+                case "System":
+                case "System.Core":
+                case "Microsoft.Build.Tasks.CodeAnalysis.resources":
+                    // These are failures are expected by design.
+                    break;
+                default:
+                    s_failedLoadSet.TryAdd(name, 0);
+                    break;
             }
         }
     }