diff --git a/src/libraries/System.Private.CoreLib/src/System/Text/Ascii.Utility.cs b/src/libraries/System.Private.CoreLib/src/System/Text/Ascii.Utility.cs
index 824c51e9a028be..90147e8b3ec69d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Text/Ascii.Utility.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Text/Ascii.Utility.cs
@@ -2200,11 +2200,21 @@ private static unsafe void WidenAsciiToUtf1_Vector<TVectorByte, TVectorUShort>(b
         private static unsafe bool HasMatch<TVectorByte>(TVectorByte vector)
             where TVectorByte : unmanaged, ISimdVector<TVectorByte, byte>
         {
+            if (typeof(TVectorByte) == typeof(Vector256<byte>))
+            {
+                return (((Vector256<byte>)(object)vector).ExtractMostSignificantBits() != 0);
+            }
+            else if (typeof(TVectorByte) == typeof(Vector512<byte>))
+            {
+                return (((Vector512<byte>)(object)vector).ExtractMostSignificantBits() != 0);
+            }
+
             if (AdvSimd.IsSupported && typeof(TVectorByte) == typeof(Vector128<byte>))
             {
                 return VectorContainsNonAsciiChar((Vector128<byte>)(object)vector);
             }
-            return ((vector & TVectorByte.Create((byte)0b1000_0000)) != TVectorByte.Zero);
+
+            return (((Vector128<byte>)(object)vector).ExtractMostSignificantBits() != 0);
         }