diff --git a/clang/include/clang/AST/ASTTypeTraits.h b/clang/include/clang/AST/ASTTypeTraits.h
--- a/clang/include/clang/AST/ASTTypeTraits.h
+++ b/clang/include/clang/AST/ASTTypeTraits.h
@@ -529,18 +529,6 @@
   }
 };
 
-// Previously these types were defined in the clang::ast_type_traits namespace.
-// Provide typedefs so that legacy code can be fixed asynchronously.
-namespace ast_type_traits {
-using DynTypedNode = ::clang::DynTypedNode;
-using ASTNodeKind = ::clang::ASTNodeKind;
-using TraversalKind = ::clang::TraversalKind;
-
-constexpr TraversalKind TK_AsIs = ::clang::TK_AsIs;
-constexpr TraversalKind TK_IgnoreUnlessSpelledInSource =
-    ::clang::TK_IgnoreUnlessSpelledInSource;
-} // namespace ast_type_traits
-
 } // end namespace clang
 
 namespace llvm {