diff --git a/llvm/include/llvm/Support/Endian.h b/llvm/include/llvm/Support/Endian.h
index 9bfe46022859c..e0afeabbcf34a 100644
--- a/llvm/include/llvm/Support/Endian.h
+++ b/llvm/include/llvm/Support/Endian.h
@@ -22,14 +22,22 @@
 #include <type_traits>
 
 namespace llvm {
-namespace support {
 
-enum endianness {
+enum class endianness {
   big,
   little,
   native = llvm::sys::IsBigEndianHost ? big : little
 };
 
+namespace support {
+
+// TODO: Remove the following once we are done migrating to llvm::endianness,
+// llvm::endianness::big, etc.
+using endianness = llvm::endianness;
+constexpr llvm::endianness big = llvm::endianness::big;
+constexpr llvm::endianness little = llvm::endianness::little;
+constexpr llvm::endianness native = llvm::endianness::native;
+
 // These are named values for common alignments.
 enum {aligned = 0, unaligned = 1};