diff --git a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
index 2898e505e324..8735ca08e3e2 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
@@ -58,7 +58,7 @@ public:
         FnAttrs.hasAttribute(AttributeSet::FunctionIndex,
                              Attribute::OptimizeForSize) ||
         FnAttrs.hasAttribute(AttributeSet::FunctionIndex, Attribute::MinSize);
-    Subtarget = &static_cast<const AArch64Subtarget &>(MF.getSubtarget());
+    Subtarget = &MF.getSubtarget<AArch64Subtarget>();
     return SelectionDAGISel::runOnMachineFunction(MF);
   }