diff --git a/lib/Target/AArch64/AArch64FastISel.cpp b/lib/Target/AArch64/AArch64FastISel.cpp
index 6456796a21e..448a171d073 100644
--- a/lib/Target/AArch64/AArch64FastISel.cpp
+++ b/lib/Target/AArch64/AArch64FastISel.cpp
@@ -40,7 +40,7 @@ using namespace llvm;
 
 namespace {
 
-class AArch64FastISel : public FastISel {
+class AArch64FastISel final : public FastISel {
   class Address {
   public:
     typedef enum {