diff --git a/test/default/auth5.c b/test/default/auth5.c
index 44fce2a1..7cdc819a 100644
--- a/test/default/auth5.c
+++ b/test/default/auth5.c
@@ -12,7 +12,6 @@ unsigned char a[32];
 int main(void)
 {
   int clen;
-  int i;
   for (clen = 0;clen < 10000;++clen) {
     randombytes(key,sizeof key);
     randombytes(c,clen);
diff --git a/test/default/box7.c b/test/default/box7.c
index 1e146767..ea7b484e 100644
--- a/test/default/box7.c
+++ b/test/default/box7.c
@@ -14,8 +14,8 @@ unsigned char m2[10000];
 
 int main(void)
 {
-  int mlen;
-  int i;
+  size_t mlen;
+  size_t i;
 
   for (mlen = 0;mlen < 1000 && mlen + crypto_box_ZEROBYTES < sizeof m;++mlen) {
     crypto_box_keypair(alicepk,alicesk);
diff --git a/test/default/box8.c b/test/default/box8.c
index 5ecc51aa..5567c8e4 100644
--- a/test/default/box8.c
+++ b/test/default/box8.c
@@ -16,8 +16,8 @@ unsigned char m2[10000];
 
 int main(void)
 {
-  int mlen;
-  int i;
+  size_t mlen;
+  size_t i;
   int caught;
 
   for (mlen = 0;mlen < 1000 && mlen + crypto_box_ZEROBYTES < sizeof m;++mlen) {
diff --git a/test/default/generichash.c b/test/default/generichash.c
index 26cc2d05..42a4a394 100644
--- a/test/default/generichash.c
+++ b/test/default/generichash.c
@@ -9,7 +9,7 @@ int main(void)
 {
 #define MAXLEN 64
     crypto_uint8 in[MAXLEN], out[crypto_generichash_BYTES_MAX], k[crypto_generichash_KEYBYTES_MAX];
-    int h,i,j;
+    size_t h,i,j;
 
     for(h = 0; h < crypto_generichash_KEYBYTES_MAX; ++h) k[h] = h;
 
diff --git a/test/default/onetimeauth7.c b/test/default/onetimeauth7.c
index 268f33d4..a12a40ab 100644
--- a/test/default/onetimeauth7.c
+++ b/test/default/onetimeauth7.c
@@ -12,7 +12,6 @@ unsigned char a[16];
 int main(void)
 {
   int clen;
-  int i;
   for (clen = 0;clen < 10000;++clen) {
     randombytes(key,sizeof key);
     randombytes(c,clen);
diff --git a/test/default/secretbox7.c b/test/default/secretbox7.c
index 9c8e0c55..337f081b 100644
--- a/test/default/secretbox7.c
+++ b/test/default/secretbox7.c
@@ -11,8 +11,8 @@ unsigned char m2[10000];
 
 int main(void)
 {
-  int mlen;
-  int i;
+  size_t mlen;
+  size_t i;
 
   for (mlen = 0;mlen < 1000 && mlen + crypto_secretbox_ZEROBYTES < sizeof m;++mlen) {
     randombytes(k,crypto_secretbox_KEYBYTES);
diff --git a/test/default/secretbox8.c b/test/default/secretbox8.c
index 1185bc46..6159b6af 100644
--- a/test/default/secretbox8.c
+++ b/test/default/secretbox8.c
@@ -13,8 +13,8 @@ unsigned char m2[10000];
 
 int main(void)
 {
-  int mlen;
-  int i;
+  size_t mlen;
+  size_t i;
   int caught;
 
   for (mlen = 0;mlen < 1000 && mlen + crypto_secretbox_ZEROBYTES < sizeof m;++mlen) {