diff --git a/lib/HLSL/DxilPreparePasses.cpp b/lib/HLSL/DxilPreparePasses.cpp
index 4b45394c7..c56a192aa 100644
--- a/lib/HLSL/DxilPreparePasses.cpp
+++ b/lib/HLSL/DxilPreparePasses.cpp
@@ -388,8 +388,8 @@ public:
       if (!F)
         continue;
       Type *Ty = OP::GetOverloadType(fromOpcode, F);
-      for (auto uit = F->user_begin(); uit != F->user_end(); uit++) {
-        CallInst *CI = cast<CallInst>(*uit);
+      for (auto uit = F->user_begin(), E = F->user_end(); uit != E;) {
+        CallInst *CI = cast<CallInst>(*(uit++));
         IRBuilder<> Builder(CI);
         std::vector<Value*> args;
         args.emplace_back(hlslOp->GetU32Const((unsigned)toOpcode));
diff --git a/tools/clang/test/HLSLFileCheck/hlsl/objects/Texture/gatherOffset2.hlsl b/tools/clang/test/HLSLFileCheck/hlsl/objects/Texture/gatherOffset2.hlsl
new file mode 100644
index 000000000..29d5c780e
--- /dev/null
+++ b/tools/clang/test/HLSLFileCheck/hlsl/objects/Texture/gatherOffset2.hlsl
@@ -0,0 +1,15 @@
+// RUN: %dxc -T ps_6_0 %s | FileCheck %s
+
+// Test for access violation that previously occured with these gathers
+
+// CHECK: @main
+
+Texture2D<float> shadowMap;
+SamplerComparisonState BilinearClampCmpSampler;
+SamplerState BilinearClampSampler;
+
+float4 main(float3 uv_depth: TEXCOORD0): SV_Target
+{
+    return shadowMap.GatherCmp(BilinearClampCmpSampler, uv_depth.xy, uv_depth.z, int2(0, 0))
+    + shadowMap.GatherRed(BilinearClampSampler, uv_depth.xy, int2(0, 0));
+}