diff --git a/stl/inc/__msvc_int128.hpp b/stl/inc/__msvc_int128.hpp
index e7d9650ff8..99c78af752 100644
--- a/stl/inc/__msvc_int128.hpp
+++ b/stl/inc/__msvc_int128.hpp
@@ -158,7 +158,12 @@ struct alignas(16) _Base128 {
         if (!_Is_constant_evaluated()) {
             return _umul128(_Left, _Right, &_High_result);
         }
-#endif // _STL_128_INTRINSICS
+#elif (defined(_M_ARM64) || defined(_M_ARM64EC)) && !defined(_M_CEE_PURE)
+        if (!_Is_constant_evaluated()) {
+            _High_result = __umulh(_Left, _Right);
+            return _Left * _Right;
+        }
+#endif // ^^^ (defined(_M_ARM64) || defined(_M_ARM64EC)) && !defined(_M_CEE_PURE) ^^^
 
         const uint32_t __u[2] = {
             static_cast<uint32_t>(_Left),