diff --git a/libtommath/bn_mp_prime_next_prime.c b/libtommath/bn_mp_prime_next_prime.c
index a2da345..b2efadd 100644
--- a/libtommath/bn_mp_prime_next_prime.c
+++ b/libtommath/bn_mp_prime_next_prime.c
@@ -143,7 +143,7 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style)
 
       /* is this prime? */
       for (x = 0; x < t; x++) {
-          mp_set(&b, ltm_prime_tab[t]);
+          mp_set(&b, ltm_prime_tab[x]);
           if ((err = mp_prime_miller_rabin(a, &b, &res)) != MP_OKAY) {
              goto LBL_ERR;
           }