diff --git a/lib/CodeGen/AllocationOrder.cpp b/lib/CodeGen/AllocationOrder.cpp
index 1005f10..87f6431 100644
--- a/lib/CodeGen/AllocationOrder.cpp
+++ b/lib/CodeGen/AllocationOrder.cpp
@@ -41,7 +41,7 @@
   if (HintPair.first) {
     const TargetRegisterInfo &TRI = VRM.getTargetRegInfo();
     // The remaining allocation order may depend on the hint.
-    ArrayRef<unsigned> Order =
+    ArrayRef<uint16_t> Order =
       TRI.getRawAllocationOrder(RC, HintPair.first, Hint,
                                 VRM.getMachineFunction());
     if (Order.empty())