diff --git a/AMBuildScript b/AMBuildScript
index 3a99d32..6a2e0a5 100644
--- a/AMBuildScript
+++ b/AMBuildScript
@@ -338,6 +338,9 @@ class MMSConfig(object):
 
   def HL2Library(self, context, compiler, name, sdk):
     binary = self.Library(compiler, name)
+    binary.sources += [
+      os.path.join(context.sourcePath, 'third_party', 'amtl', 'compat', 'stdcxx.cpp'),
+    ]
     cxx = binary.compiler
 
     cxx.cxxincludes += [
diff --git a/third_party/amtl b/third_party/amtl
index ad9d5c3..285b4f8 160000
--- a/third_party/amtl
+++ b/third_party/amtl
@@ -1 +1 @@
-Subproject commit ad9d5c33534dcfd902e2aeb0744df1a227b1c6d3
+Subproject commit 285b4f853c0003023838140113e3ec066bd800c6