diff --git a/examples/utils.h b/examples/utils.h
index 70180370..a7ecdd25 100644
--- a/examples/utils.h
+++ b/examples/utils.h
@@ -56,7 +56,9 @@ prompt_input(const char *prompt, char *input, const size_t max_input_len,
         printf("\nEnter %s (%zu bytes) > ", prompt, max_input_len);
     }
     fflush(stdout);
-    fgets(input_tmp, sizeof input_tmp, stdin);
+    if (fgets(input_tmp, sizeof input_tmp, stdin) == NULL) {
+      input_tmp[0] = '\0';
+    }
     actual_input_len = strlen(input_tmp);
 
     /* trim \n */
diff --git a/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c b/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
index dba635a0..0319375f 100644
--- a/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
+++ b/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
@@ -86,7 +86,9 @@ sodium_hrtime(void)
 #else
     {
         struct timeval tv;
-        assert(gettimeofday(&tv, NULL) == 0);
+        int ret = gettimeofday(&tv, NULL);
+        (void)ret;
+        assert(ret == 0);
         ts = ((uint64_t) tv.tv_sec) * 1000000U + (uint64_t) tv.tv_usec;
     }
 #endif
diff --git a/test/default/auth.c b/test/default/auth.c
index 417d8026..83fc393d 100644
--- a/test/default/auth.c
+++ b/test/default/auth.c
@@ -15,7 +15,7 @@ static unsigned char a2[crypto_auth_hmacsha512_BYTES];
 int main(void)
 {
     crypto_auth_hmacsha512_state st;
-    int i;
+    size_t i;
 
     assert(crypto_auth_hmacsha512_statebytes() ==
            sizeof(crypto_auth_hmacsha512_state));