diff --git a/demos/tv_gen.c b/demos/tv_gen.c
index 7108fea..e754a7d 100644
--- a/demos/tv_gen.c
+++ b/demos/tv_gen.c
@@ -747,14 +747,14 @@ void gcm_gen(void)
 void base64_gen(void)
 {
    FILE *out;
-   unsigned char dst[256], src[32];
-   unsigned long x, y, len;
+   unsigned char dst[256], src[32], ch;
+   unsigned long x, len;
 
    out = fopen("base64_tv.txt", "w");
    fprintf(out, "Base64 vectors.  These are the base64 encodings of the strings 00,01,02...NN-1\n\n");
    for (x = 0; x <= 32; x++) {
-       for (y = 0; y < x; y++) {
-           src[y] = (unsigned char)y;
+       for (ch = 0; ch < x; ch++) {
+           src[ch] = ch;
        }
        len = sizeof(dst);
        base64_encode(src, x, dst, &len);
diff --git a/testprof/dh_test.c b/testprof/dh_test.c
index f2cc0bb..e2bd980 100644
--- a/testprof/dh_test.c
+++ b/testprof/dh_test.c
@@ -10,7 +10,7 @@
 
 int dh_test (void)
 {
-  unsigned char buf[3][4096];
+  unsigned char buf[3][4096], ch;
   unsigned long x, y, z;
   int           stat, stat2;
   dh_key        usera, userb;
@@ -74,8 +74,8 @@ int dh_test (void)
 
 /* test encrypt_key */
   dh_make_key (&yarrow_prng, find_prng ("yarrow"), KEYSIZE/8, &usera);
-  for (x = 0; x < 16; x++) {
-    buf[0][x] = (unsigned char)x;
+  for (ch = 0; ch < 16; ch++) {
+    buf[0][ch] = ch;
   }
   y = sizeof (buf[1]);
   DO(dh_encrypt_key (buf[0], 16, buf[1], &y, &yarrow_prng, find_prng ("yarrow"), find_hash ("md5"), &usera));
@@ -87,16 +87,16 @@ int dh_test (void)
     dh_free (&usera);
     return 1;
   }
-  for (x = 0; x < 16; x++)
-    if (buf[0][x] != x) {
+  for (ch = 0; ch < 16; ch++)
+    if (buf[0][ch] != ch) {
       fprintf(stderr, "Failed (contents)\n");
       dh_free (&usera);
       return 1;
     }
 
 /* test sign_hash */
-  for (x = 0; x < 16; x++) {
-     buf[0][x] = (unsigned char)x;
+  for (ch = 0; ch < 16; ch++) {
+     buf[0][ch] = ch;
   }
   x = sizeof (buf[1]);
   DO(dh_sign_hash (buf[0], 16, buf[1], &x, &yarrow_prng, find_prng ("yarrow"), &usera));
diff --git a/testprof/dsa_test.c b/testprof/dsa_test.c
index 5db4edf..37f06d7 100644
--- a/testprof/dsa_test.c
+++ b/testprof/dsa_test.c
@@ -171,7 +171,7 @@ static int dsa_compat_test(void)
 
 int dsa_test(void)
 {
-   unsigned char msg[16], out[1024], out2[1024];
+   unsigned char msg[16], out[1024], out2[1024], ch;
    unsigned long x, y;
    int stat1, stat2;
    dsa_key key, key2;
@@ -186,7 +186,7 @@ int dsa_test(void)
    if (stat1 == 0) { fprintf(stderr, "dsa_verify_key "); return 1; }
 
    /* encrypt a message */
-   for (x = 0; x < 16; x++) { msg[x] = (unsigned char)x; }
+   for (ch = 0; ch < 16; ch++) { msg[ch] = ch; }
    x = sizeof(out);
    DO(dsa_encrypt_key(msg, 16, out, &x, &yarrow_prng, find_prng("yarrow"), find_hash("sha1"), &key));
 
diff --git a/testprof/ecc_test.c b/testprof/ecc_test.c
index 069e27b..b4668d0 100644
--- a/testprof/ecc_test.c
+++ b/testprof/ecc_test.c
@@ -107,7 +107,7 @@ int ecc_test_shamir(void)
 
 int ecc_tests (void)
 {
-  unsigned char buf[4][4096];
+  unsigned char buf[4][4096], ch;
   unsigned long x, y, z, s;
   int           stat, stat2;
   ecc_key usera, userb, pubKey, privKey;
@@ -191,8 +191,8 @@ int ecc_tests (void)
      DO(ecc_export(buf[0], &x, PK_PRIVATE, &usera));
      DO(ecc_import(buf[0], x, &privKey));
 
-     for (x = 0; x < 32; x++) {
-        buf[0][x] = (unsigned char)x;
+     for (ch = 0; ch < 32; ch++) {
+        buf[0][ch] = ch;
      }
      y = sizeof (buf[1]);
      DO(ecc_encrypt_key (buf[0], 32, buf[1], &y, &yarrow_prng, find_prng ("yarrow"), find_hash ("sha256"), &pubKey));
@@ -203,15 +203,15 @@ int ecc_tests (void)
        fprintf(stderr, "Failed (length)");
        return 1;
      }
-     for (x = 0; x < 32; x++) {
-        if (buf[0][x] != x) {
+     for (ch = 0; ch < 32; ch++) {
+        if (buf[0][ch] != ch) {
            fprintf(stderr, "Failed (contents)");
            return 1;
         }
      }
      /* test sign_hash */
-     for (x = 0; x < 16; x++) {
-        buf[0][x] = (unsigned char)x;
+     for (ch = 0; ch < 16; ch++) {
+        buf[0][ch] = ch;
      }
      x = sizeof (buf[1]);
      DO(ecc_sign_hash (buf[0], 16, buf[1], &x, &yarrow_prng, find_prng ("yarrow"), &privKey));