diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
index 8653265..76ef5c0 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
@@ -70,8 +70,10 @@
         MachineOperand &MO = MI.getOperand(0);
         unsigned OldReg = MO.getReg();
         // TODO: Handle SP/physregs
-        if (OldReg == MI.getOperand(3).getReg() &&
-            TargetRegisterInfo::isVirtualRegister(MI.getOperand(3).getReg())) {
+        if (OldReg ==
+                MI.getOperand(WebAssembly::StoreValueOperandNo).getReg() &&
+            TargetRegisterInfo::isVirtualRegister(
+                MI.getOperand(WebAssembly::StoreValueOperandNo).getReg())) {
           Changed = true;
           unsigned NewReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
           MO.setReg(NewReg);