diff --git a/llvm/lib/Target/DirectX/DXILFlattenArrays.cpp b/llvm/lib/Target/DirectX/DXILFlattenArrays.cpp
index f0e2e786dfaf4..7e1436e05a34a 100644
--- a/llvm/lib/Target/DirectX/DXILFlattenArrays.cpp
+++ b/llvm/lib/Target/DirectX/DXILFlattenArrays.cpp
@@ -263,8 +263,13 @@ bool DXILFlattenArraysVisitor::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   // merge the byte offsets. Otherwise, this GEP is itself the root of a GEP
   // chain and we need to deterine the root array type
   if (auto *PtrOpGEP = dyn_cast<GEPOperator>(PtrOperand)) {
-    assert(GEPChainInfoMap.contains(PtrOpGEP) &&
-           "Expected parent GEP to be visited before this GEP");
+
+    // If the parent GEP was not processed, then we do not want to process its
+    // descendants. This can happen if the GEP chain is for an unsupported type
+    // such as a struct -- we do not flatten structs nor GEP chains for structs
+    if (!GEPChainInfoMap.contains(PtrOpGEP))
+      return false;
+
     GEPInfo &PGEPInfo = GEPChainInfoMap[PtrOpGEP];
     Info.RootFlattenedArrayType = PGEPInfo.RootFlattenedArrayType;
     Info.RootPointerOperand = PGEPInfo.RootPointerOperand;
diff --git a/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll b/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll
index 40d222cdf2f8f..e6d4c1ee936a9 100644
--- a/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll
+++ b/llvm/test/CodeGen/DirectX/issue-145408-gep-struct-fix.ll
@@ -8,10 +8,12 @@ define void @test_no_transform_of_struct()  {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
 ; CHECK-NEXT:    [[OUTPUTSIZESLOCAL_I:%.*]] = alloca [[STRUCT_RAWSTRUCT8D:%.*]], align 4
 ; CHECK-NEXT:    [[ARRAYINIT_ELEMENT13_I76:%.*]] = getelementptr inbounds nuw [1 x %struct.RawStruct8D], ptr [[OUTPUTSIZESLOCAL_I]], i32 0, i32 0
+; CHECK-NEXT:    [[ARRAYINIT_ELEMENT13_I76_I1:%.*]] = getelementptr inbounds nuw [8 x i32], ptr [[ARRAYINIT_ELEMENT13_I76]], i32 0, i32 1
 ; CHECK-NEXT:    ret void
 ;
 entry:
   %outputSizesLocal.i = alloca %struct.RawStruct8D, align 4
   %arrayinit.element13.i76 = getelementptr inbounds nuw [1 x %struct.RawStruct8D], ptr %outputSizesLocal.i, i32 0, i32 0
+  %arrayinit.element13.i76.i1 = getelementptr inbounds nuw [8 x i32], ptr %arrayinit.element13.i76, i32 0, i32 1
   ret void
 }