diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index a15042f1a0ee..07cd10d6d22d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -1215,8 +1215,8 @@ static Instruction *foldInsEltIntoSplat(InsertElementInst &InsElt) {
 
   // Replace the shuffle mask element at the index of this insert with a zero.
   // For example:
-  // inselt (shuf (inselt undef, X, 0), undef, <0,undef,0,undef>), X, 1
-  //   --> shuf (inselt undef, X, 0), undef, <0,0,0,undef>
+  // inselt (shuf (inselt undef, X, 0), _, <0,undef,0,undef>), X, 1
+  //   --> shuf (inselt undef, X, 0), poison, <0,0,0,undef>
   unsigned NumMaskElts =
       cast<FixedVectorType>(Shuf->getType())->getNumElements();
   SmallVector<int, 16> NewMask(NumMaskElts);
@@ -1973,8 +1973,8 @@ static Instruction *canonicalizeInsertSplat(ShuffleVectorInst &Shuf,
 
   // Splat from element 0. Any mask element that is undefined remains undefined.
   // For example:
-  // shuf (inselt undef, X, 2), undef, <2,2,undef>
-  //   --> shuf (inselt undef, X, 0), undef, <0,0,undef>
+  // shuf (inselt undef, X, 2), _, <2,2,undef>
+  //   --> shuf (inselt undef, X, 0), poison, <0,0,undef>
   unsigned NumMaskElts =
       cast<FixedVectorType>(Shuf.getType())->getNumElements();
   SmallVector<int, 16> NewMask(NumMaskElts, 0);