diff --git a/include/fast_float/digit_comparison.h b/include/fast_float/digit_comparison.h
index 435a2c8..6984837 100644
--- a/include/fast_float/digit_comparison.h
+++ b/include/fast_float/digit_comparison.h
@@ -347,6 +347,15 @@ parse_mantissa(bigint &result, const parsed_number_string_t<UC> &num) noexcept {
     }
     // process all digits, in increments of step per loop
     while (p != pend) {
+#if defined(FASTFLOAT_64BIT_LIMB) && defined(FASTFLOAT_X86_SIMD) &&            \
+    FASTFLOAT_X86_SIMD >= 31
+      if FASTFLOAT_CONSTEXPR17 (sizeof(UC) == 1) {
+        if (!is_constant_evaluated() && (std::distance(p, pend) >= 16) &&
+            (step - counter >= 16) && (max_digits - digits >= 16)) {
+          parse_sixteen_digits(p, value, counter, digits);
+        }
+      }
+#endif
       while ((std::distance(p, pend) >= 8) && (step - counter >= 8) &&
              (max_digits - digits >= 8)) {
         parse_eight_digits(p, value, counter, digits);