diff --git a/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp b/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
index 526305d7ed28a..892912a568011 100644
--- a/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
@@ -990,13 +990,13 @@ bool SPIRVInstructionSelector::selectMemOperation(Register ResVReg,
     Register VarReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
     GR.add(GV, GR.CurMF, VarReg);
 
-    buildOpDecorate(VarReg, I, TII, SPIRV::Decoration::Constant, {});
     BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpVariable))
         .addDef(VarReg)
         .addUse(GR.getSPIRVTypeID(VarTy))
         .addImm(SPIRV::StorageClass::UniformConstant)
         .addUse(Const)
         .constrainAllUses(TII, TRI, RBI);
+    buildOpDecorate(VarReg, I, TII, SPIRV::Decoration::Constant, {});
     SPIRVType *SourceTy = GR.getOrCreateSPIRVPointerType(
         ValTy, I, TII, SPIRV::StorageClass::UniformConstant);
     SrcReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
diff --git a/llvm/lib/Target/SPIRV/SPIRVPreLegalizer.cpp b/llvm/lib/Target/SPIRV/SPIRVPreLegalizer.cpp
index cc34cf877dea9..790d86f191fd8 100644
--- a/llvm/lib/Target/SPIRV/SPIRVPreLegalizer.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVPreLegalizer.cpp
@@ -829,7 +829,7 @@ static void insertSpirvDecorations(MachineFunction &MF, MachineIRBuilder MIB) {
     for (MachineInstr &MI : MBB) {
       if (!isSpvIntrinsic(MI, Intrinsic::spv_assign_decoration))
         continue;
-      MIB.setInsertPt(*MI.getParent(), MI);
+      MIB.setInsertPt(*MI.getParent(), MI.getNextNode());
       buildOpSpirvDecorations(MI.getOperand(1).getReg(), MIB,
                               MI.getOperand(2).getMetadata());
       ToErase.push_back(&MI);
diff --git a/llvm/test/CodeGen/SPIRV/decoration-order.ll b/llvm/test/CodeGen/SPIRV/decoration-order.ll
new file mode 100644
index 0000000000000..e8299e9735a06
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/decoration-order.ll
@@ -0,0 +1,15 @@
+; RUN: %if spirv-tools %{ llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+; This test checks the OpDecorate MIR is generated after the associated
+; vreg definition in the case of an array size declared through this lowering.
+
+define spir_func i32 @foo() {
+entry:
+  %var = alloca i64
+  br label %block
+
+block:
+  call void @llvm.memset.p0.i64(ptr align 8 %var, i8 0, i64 24, i1 false)
+  ret i32 0
+}
+
+declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg)