diff --git a/tests/kat_kem.c b/tests/kat_kem.c
index a858868590..314b20b510 100644
--- a/tests/kat_kem.c
+++ b/tests/kat_kem.c
@@ -33,7 +33,7 @@ static OQS_STATUS kem_kat(const char *method_name, bool all) {
 	uint8_t *shared_secret_d = NULL;
 	OQS_STATUS rc, ret = OQS_ERROR;
 	int rv;
-	int max_count;
+	size_t max_count;
 	OQS_KAT_PRNG *prng;
 
 	prng = OQS_KAT_PRNG_new(method_name);
@@ -67,8 +67,8 @@ static OQS_STATUS kem_kat(const char *method_name, bool all) {
 
 	max_count = all ? prng->max_kats : 1;
 
-	for (int count = 0; count < max_count; ++count) {
-		fprintf(fh, "count = %d\n", count);
+	for (size_t count = 0; count < max_count; ++count) {
+		fprintf(fh, "count = %zu\n", count);
 		OQS_randombytes(seed, 48);
 		OQS_fprintBstr(fh, "seed = ", seed, 48);
 
diff --git a/tests/kat_sig.c b/tests/kat_sig.c
index 89e1f27e2b..9a3542cf49 100644
--- a/tests/kat_sig.c
+++ b/tests/kat_sig.c
@@ -244,7 +244,7 @@ OQS_STATUS sig_kat(const char *method_name, bool all) {
 	size_t signed_msg_len = 0;
 	OQS_STATUS rc, ret = OQS_ERROR;
 	OQS_KAT_PRNG *prng = NULL;
-	int max_count;
+	size_t max_count;
 
 	prng = OQS_KAT_PRNG_new(method_name);
 	if (prng == NULL) {
@@ -277,8 +277,8 @@ OQS_STATUS sig_kat(const char *method_name, bool all) {
 		goto err;
 	}
 
-	for (int count = 0; count < max_count; ++count) {
-		fprintf(fh, "count = %d\n", count);
+	for (size_t count = 0; count < max_count; ++count) {
+		fprintf(fh, "count = %zu\n", count);
 		OQS_randombytes(seed, 48);
 		OQS_fprintBstr(fh, "seed = ", seed, 48);
 
diff --git a/tests/test_helpers.h b/tests/test_helpers.h
index 4dfffb61db..5b1c17d7bc 100644
--- a/tests/test_helpers.h
+++ b/tests/test_helpers.h
@@ -14,7 +14,7 @@ typedef union {
 } OQS_KAT_PRNG_state;
 
 typedef struct {
-	int max_kats;
+	size_t max_kats;
 	OQS_KAT_PRNG_state saved_state;
 	// The caller should use the OQS_KAT_PRNG_* functions instead of these callbacks.
 	void (*seed)(const uint8_t *, const uint8_t *);