diff --git a/demo/test.c b/demo/test.c
index 281255b..e1b6f0f 100644
--- a/demo/test.c
+++ b/demo/test.c
@@ -729,7 +729,7 @@ static int test_mp_sqrt(void)
          printf("\nmp_sqrt() error!");
          goto LBL_ERR;
       }
-      DO(mp_root_n(&a, 2u, &c));
+      DO(mp_root_n(&a, 2, &c));
       if (mp_cmp_mag(&b, &c) != MP_EQ) {
          printf("mp_sqrt() bad result!\n");
          goto LBL_ERR;
@@ -2082,16 +2082,53 @@ static int test_s_mp_div_recursive(void)
       DO(s_mp_div_recursive(&a, &b, &c_q, &c_r));
       DO(s_mp_div_school(&a, &b, &d_q, &d_r));
       if (mp_cmp(&c_q, &d_q) != MP_EQ) {
-         fprintf(stderr, "1. Recursive division failed at sizes %d / %d, wrong quotient\n",
+         fprintf(stderr, "1a. Recursive division failed at sizes %d / %d, wrong quotient\n",
                  10 * size, size);
          goto LBL_ERR;
       }
       if (mp_cmp(&c_r, &d_r) != MP_EQ) {
-         fprintf(stderr, "1. Recursive division failed at sizes %d / %d, wrong remainder\n",
+         fprintf(stderr, "1a. Recursive division failed at sizes %d / %d, wrong remainder\n",
                  10 * size, size);
          goto LBL_ERR;
       }
       printf("\rsizes = %d / %d", 2 * size, size);
+
+      /* Relation 10:1 negative numerator*/
+      DO(mp_rand(&a, 10 * size));
+      DO(mp_neg(&a, &a));
+      DO(mp_rand(&b, size));
+      DO(s_mp_div_recursive(&a, &b, &c_q, &c_r));
+      DO(s_mp_div_school(&a, &b, &d_q, &d_r));
+      if (mp_cmp(&c_q, &d_q) != MP_EQ) {
+         fprintf(stderr, "1b. Recursive division failed at sizes %d / %d, wrong quotient\n",
+                 10 * size, size);
+         goto LBL_ERR;
+      }
+      if (mp_cmp(&c_r, &d_r) != MP_EQ) {
+         fprintf(stderr, "1b. Recursive division failed at sizes %d / %d, wrong remainder\n",
+                 10 * size, size);
+         goto LBL_ERR;
+      }
+      printf("\rsizes = %d / %d, negative numerator", 2 * size, size);
+
+      /* Relation 10:1 negative denominator*/
+      DO(mp_rand(&a, 10 * size));
+      DO(mp_rand(&b, size));
+      DO(mp_neg(&b, &b));
+      DO(s_mp_div_recursive(&a, &b, &c_q, &c_r));
+      DO(s_mp_div_school(&a, &b, &d_q, &d_r));
+      if (mp_cmp(&c_q, &d_q) != MP_EQ) {
+         fprintf(stderr, "1c. Recursive division failed at sizes %d / %d, wrong quotient\n",
+                 10 * size, size);
+         goto LBL_ERR;
+      }
+      if (mp_cmp(&c_r, &d_r) != MP_EQ) {
+         fprintf(stderr, "1c. Recursive division failed at sizes %d / %d, wrong remainder\n",
+                 10 * size, size);
+         goto LBL_ERR;
+      }
+      printf("\rsizes = %d / %d, negative denominator", 2 * size, size);
+
       /* Relation 2:1 */
       DO(mp_rand(&a, 2 * size));
       DO(mp_rand(&b, size));
@@ -2326,7 +2363,7 @@ static int unit_tests(int argc, char **argv)
       T1(mp_set_double, MP_SET_DOUBLE),
 #endif
       T1(mp_signed_rsh, MP_SIGNED_RSH),
-      T2(mp_sqrt, MP_SQRT, mp_root_n),
+      T2(mp_sqrt, MP_SQRT, MP_ROOT_N),
       T1(mp_sqrtmod_prime, MP_SQRTMOD_PRIME),
       T1(mp_xor, MP_XOR),
       T2(s_mp_div_recursive, S_MP_DIV_RECURSIVE, S_MP_DIV_SCHOOL),
diff --git a/s_mp_div_recursive.c b/s_mp_div_recursive.c
index 5491f22..df9a297 100644
--- a/s_mp_div_recursive.c
+++ b/s_mp_div_recursive.c
@@ -159,7 +159,7 @@ mp_err s_mp_div_recursive(const mp_int *a, const mp_int *b, mp_int *q, mp_int *r
    if ((err = mp_add(&Q, &Q1, &Q)) != MP_OKAY)                                   goto LBL_ERR;
 
    /* get sign before writing to c */
-   Q.sign = (mp_iszero(&Q) ? MP_ZPOS : a->sign);
+   R.sign = (mp_iszero(&Q) ? MP_ZPOS : a->sign);
 
    if (q != NULL) {
       mp_exch(&Q, q);