diff --git a/tests/api.c b/tests/api.c
index f28d0b87f..be2e6be26 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -13944,7 +13944,7 @@ static void test_wolfSSL_PEM_PrivateKey(void)
     #ifdef HAVE_ECC
     {
         unsigned char buf[2048];
-        int bytes;
+        size_t bytes;
         XFILE f;
         SSL_CTX* ctx;