diff --git a/etc/2kprime.c b/etc/2kprime.c
index 55cb5f48f..95ed2de42 100644
--- a/etc/2kprime.c
+++ b/etc/2kprime.c
@@ -8,7 +8,7 @@ int main(void)
 {
    char buf[2000];
    size_t x;
-   int y;
+   mp_bool y;
    mp_int q, p;
    FILE *out;
    clock_t t1;
@@ -43,7 +43,7 @@ int main(void)
 
             /* quick test on q */
             mp_prime_is_prime(&q, 1, &y);
-            if (y == 0) {
+            if (y == MP_NO) {
                continue;
             }
 
@@ -51,20 +51,20 @@ int main(void)
             mp_sub_d(&q, 1uL, &p);
             mp_div_2(&p, &p);
             mp_prime_is_prime(&p, 3, &y);
-            if (y == 0) {
+            if (y == MP_NO) {
                continue;
             }
 
             /* test on q */
             mp_prime_is_prime(&q, 3, &y);
-            if (y == 0) {
+            if (y == MP_NO) {
                continue;
             }
 
             break;
          }
 
-         if (y == 0) {
+         if (y == MP_NO) {
             ++sizes[x];
             goto top;
          }
diff --git a/etc/drprime.c b/etc/drprime.c
index 146455e58..64e31ef10 100644
--- a/etc/drprime.c
+++ b/etc/drprime.c
@@ -5,7 +5,8 @@ static int sizes[] = { 1+256/MP_DIGIT_BIT, 1+512/MP_DIGIT_BIT, 1+768/MP_DIGIT_BI
 
 int main(void)
 {
-   int res, x, y;
+   mp_bool res;
+   int x, y;
    char buf[4096];
    FILE *out;
    mp_int a, b;
@@ -29,23 +30,23 @@ int main(void)
          a.used = sizes[x];
 
          /* now loop */
-         res = 0;
+         res = MP_NO;
          for (;;) {
             a.dp[0] += 4uL;
             if (a.dp[0] >= MP_MASK) break;
             mp_prime_is_prime(&a, 1, &res);
-            if (res == 0) continue;
+            if (res == MP_NO) continue;
             printf(".");
             fflush(stdout);
             mp_sub_d(&a, 1uL, &b);
             mp_div_2(&b, &b);
             mp_prime_is_prime(&b, 3, &res);
-            if (res == 0) continue;
+            if (res == MP_NO) continue;
             mp_prime_is_prime(&a, 3, &res);
-            if (res == 1) break;
+            if (res == MP_YES) break;
          }
 
-         if (res != 1) {
+         if (res != MP_YES) {
             printf("Error not DR modulus\n");
             sizes[x] += 1;
             goto top;
diff --git a/etc/mersenne.c b/etc/mersenne.c
index f6d7cb632..0c9f52fcf 100644
--- a/etc/mersenne.c
+++ b/etc/mersenne.c
@@ -5,12 +5,13 @@
 #include <time.h>
 #include <tommath.h>
 
-static int is_mersenne(long s, int *pp)
+static mp_err is_mersenne(long s, mp_bool *pp)
 {
    mp_int  n, u;
-   int     res, k;
+   mp_err  res;
+   int     k;
 
-   *pp = 0;
+   *pp = MP_NO;
 
    if ((res = mp_init(&n)) != MP_OKAY) {
       return res;
@@ -55,9 +56,9 @@ static int is_mersenne(long s, int *pp)
    }
 
    /* if u == 0 then its prime */
-   if (mp_iszero(&u) == 1) {
+   if (mp_iszero(&u) == MP_YES) {
       mp_prime_is_prime(&n, 8, pp);
-      if (*pp != 1) printf("FAILURE\n");
+      if (*pp != MP_YES) printf("FAILURE\n");
    }
 
    res = MP_OKAY;
@@ -102,7 +103,7 @@ static int isprime(long k)
 
 int main(void)
 {
-   int     pp;
+   mp_bool pp;
    long    k;
    clock_t tt;
 
@@ -118,7 +119,7 @@ int main(void)
          return -1;
       }
 
-      if (pp == 1) {
+      if (pp == MP_YES) {
          /* count time */
          tt = clock() - tt;
 
diff --git a/etc/pprime.c b/etc/pprime.c
index fa622f842..009a18cb9 100644
--- a/etc/pprime.c
+++ b/etc/pprime.c
@@ -179,10 +179,11 @@ static mp_digit prime_digit(void)
 
 
 /* makes a prime of at least k bits */
-static int pprime(int k, int li, mp_int *p, mp_int *q)
+static mp_err pprime(int k, int li, mp_int *p, mp_int *q)
 {
    mp_int  a, b, c, n, x, y, z, v;
-   int     res, ii;
+   mp_err  res;
+   int     ii;
    static const mp_digit bases[] = { 2, 3, 5, 7, 11, 13, 17, 19 };
 
    /* single digit ? */
diff --git a/etc/tune.c b/etc/tune.c
index 389ce2f69..2260a701b 100644
--- a/etc/tune.c
+++ b/etc/tune.c
@@ -61,7 +61,8 @@ static int s_offset = 1;
 #define s_mp_mul(a, b, c) s_mp_mul_digs(a, b, c, (a)->used + (b)->used + 1)
 static uint64_t s_time_mul(int size)
 {
-   int x, e;
+   int x;
+   mp_err  e;
    mp_int  a, b, c, d;
    uint64_t t1;
 
@@ -106,7 +107,8 @@ static uint64_t s_time_mul(int size)
 
 static uint64_t s_time_sqr(int size)
 {
-   int x, e;
+   int x;
+   mp_err  e;
    mp_int  a, b, c;
    uint64_t t1;
 
diff --git a/mp_prime_next_prime.c b/mp_prime_next_prime.c
index 3e2571a72..f8b22129e 100644
--- a/mp_prime_next_prime.c
+++ b/mp_prime_next_prime.c
@@ -10,9 +10,10 @@
  */
 mp_err mp_prime_next_prime(mp_int *a, int t, int bbs_style)
 {
-   int      x, y, cmp;
-   mp_err  err;
-   mp_bool res = MP_NO;
+   int      x, y;
+   mp_ord   cmp;
+   mp_err   err;
+   mp_bool  res = MP_NO;
    mp_digit res_tab[MP_PRIME_TAB_SIZE], step, kstep;
    mp_int   b;
 
diff --git a/s_mp_toom_mul.c b/s_mp_toom_mul.c
index 0b2d57d72..93113b80c 100644
--- a/s_mp_toom_mul.c
+++ b/s_mp_toom_mul.c
@@ -32,7 +32,8 @@
 mp_err s_mp_toom_mul(const mp_int *a, const mp_int *b, mp_int *c)
 {
    mp_int S1, S2, T1, a0, a1, a2, b0, b1, b2;
-   int err, B, count;
+   int B, count;
+   mp_err err;
 
    /* init temps */
    if ((err = mp_init_multi(&S1, &S2, &T1, NULL)) != MP_OKAY) {
diff --git a/s_mp_toom_sqr.c b/s_mp_toom_sqr.c
index 884a532a7..67c465c6a 100644
--- a/s_mp_toom_sqr.c
+++ b/s_mp_toom_sqr.c
@@ -22,7 +22,8 @@ mp_err s_mp_toom_sqr(const mp_int *a, mp_int *b)
 {
    mp_int S0, a0, a1, a2;
    mp_digit *tmpa, *tmpc;
-   mp_err err, B, count;
+   int B, count;
+   mp_err err;
 
 
    /* init temps */
diff --git a/tommath.h b/tommath.h
index b82477e05..29e9b207a 100644
--- a/tommath.h
+++ b/tommath.h
@@ -123,7 +123,7 @@ typedef enum {
    MP_MEM   = -2,  /* out of mem */
    MP_VAL   = -3,  /* invalid input */
    MP_ITER  = -4,  /* maximum iterations reached */
-   MP_BUF   = -5,  /* buffer overflow, supplied buffer too small */
+   MP_BUF   = -5   /* buffer overflow, supplied buffer too small */
 } mp_err;
 
 typedef enum {