diff --git a/src/UTF8.cs b/src/UTF8.cs
index 4412f17..72abebd 100644
--- a/src/UTF8.cs
+++ b/src/UTF8.cs
@@ -1405,7 +1405,7 @@ private unsafe static (int utfadjust, int scalaradjust) calculateErrorPathadjust
                             if (processedLength + localasciirun + 16 <= inputLength)
                             {
                                 Vector128<byte> block = AdvSimd.LoadVector128(pInputBuffer + processedLength + localasciirun);
-                                if (AdvSimd.Arm64.MaxAcross(Vector128.AsUInt32(AdvSimd.And(block, v80))).ToScalar() == 0)
+                                if ((block & v80) == Vector128<byte>.Zero)
                                 {
                                     localasciirun += 16;
                                     for (; processedLength + localasciirun + 64 <= inputLength; localasciirun += 64)
diff --git a/test/UTF8ValidationTests.cs b/test/UTF8ValidationTests.cs
index 9b21e5f..6951c85 100644
--- a/test/UTF8ValidationTests.cs
+++ b/test/UTF8ValidationTests.cs
@@ -52,9 +52,9 @@ private static bool IsSystemSupported(TestSystemRequirements requiredSystems)
                 case Architecture.Arm64:
                     return requiredSystems.HasFlag(TestSystemRequirements.Arm64);
                 case Architecture.X64:
-                    return (requiredSystems.HasFlag(TestSystemRequirements.X64Avx512) && Vector512.IsHardwareAccelerated && System.Runtime.Intrinsics.X86.Avx512F.IsSupported) ||
+                    return (requiredSystems.HasFlag(TestSystemRequirements.X64Avx512) && Vector512.IsHardwareAccelerated && System.Runtime.Intrinsics.X86.Avx512Vbmi.IsSupported) ||
                         (requiredSystems.HasFlag(TestSystemRequirements.X64Avx2) && System.Runtime.Intrinsics.X86.Avx2.IsSupported) ||
-                        (requiredSystems.HasFlag(TestSystemRequirements.X64Sse) && System.Runtime.Intrinsics.X86.Sse.IsSupported);
+                        (requiredSystems.HasFlag(TestSystemRequirements.X64Sse) && System.Runtime.Intrinsics.X86.Ssse3.IsSupported);
                 default:
                     return false; // If architecture is not covered above, the test is not supported.
             }