diff --git a/mrbgems/mruby-bigint/core/bigint.c b/mrbgems/mruby-bigint/core/bigint.c
index cbd066fde..5cdb452c6 100644
--- a/mrbgems/mruby-bigint/core/bigint.c
+++ b/mrbgems/mruby-bigint/core/bigint.c
@@ -1485,7 +1485,36 @@ udiv(mpz_ctx_t *ctx, mpz_t *qq, mpz_t *rr, mpz_t *xx, mpz_t *yy)
       }
 
       /* Enhanced qhat refinement step */
-      if (yd > 1) {
+      if (yd > 2) { // Now considering at least 3 limbs of divisor
+        mp_dbl_limb y_second = y.p[yd-2];
+        mp_dbl_limb y_third = y.p[yd-3]; // New: third limb of divisor
+        mp_dbl_limb x_third = (j+yd-2 < x.sz) ? x.p[j+yd-2] : 0;
+        mp_dbl_limb x_fourth = (j+yd-3 < x.sz) ? x.p[j+yd-3] : 0; // New: fourth limb of dividend
+
+        // Initial check with 2 limbs
+        mp_dbl_limb left_side = qhat * y_second;
+        mp_dbl_limb right_side = (rhat << DIG_SIZE) + x_third;
+
+        while (qhat >= ((mp_dbl_limb)1 << DIG_SIZE) || (left_side > right_side)) {
+          qhat--;
+          rhat += z;
+          if (rhat >= ((mp_dbl_limb)1 << DIG_SIZE)) break;
+          left_side -= y_second;
+          right_side = (rhat << DIG_SIZE) + x_third;
+        }
+
+        // Additional check with 3 limbs (new refinement)
+        left_side = qhat * y_third;
+        right_side = (rhat << DIG_SIZE) + x_fourth;
+
+        while (qhat >= ((mp_dbl_limb)1 << DIG_SIZE) || (left_side > right_side)) {
+          qhat--;
+          rhat += z;
+          if (rhat >= ((mp_dbl_limb)1 << DIG_SIZE)) break;
+          left_side -= y_third;
+          right_side = (rhat << DIG_SIZE) + x_fourth;
+        }
+      } else if (yd == 2) { // Original 2-limb check
         mp_dbl_limb y_second = y.p[yd-2];
         mp_dbl_limb x_third = (j+yd-2 < x.sz) ? x.p[j+yd-2] : 0;
         mp_dbl_limb left_side = qhat * y_second;