diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index af96316e4b15..77546ae06357 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -11661,7 +11661,7 @@ static SDValue lowerV4X128VectorShuffle(SDLoc DL, MVT VT,
 
   // To handle 256 bit vector requires VLX and most probably
   // function lowerV2X128VectorShuffle() is better solution.
-  assert(VT.is512BitVector() && "Unexpected vector size for 128bit shuffle.");
+  assert(VT.is512BitVector() && "Unexpected vector size for 512bit shuffle.");
 
   SmallVector<int, 4> WidenedMask;
   if (!canWidenShuffleElements(Mask, WidenedMask))