diff --git a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
index 64531d7e4017..1d0cdc85a15b 100644
--- a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
@@ -815,6 +815,7 @@ bool AArch64InstructionSelector::select(MachineInstr &I,
   case TargetOpcode::G_EXTRACT: {
     LLT SrcTy = MRI.getType(I.getOperand(1).getReg());
     LLT DstTy = MRI.getType(I.getOperand(0).getReg());
+    (void)DstTy;
     unsigned SrcSize = SrcTy.getSizeInBits();
     // Larger extracts are vectors, same-size extracts should be something else
     // by now (either split up or simplified to a COPY).