diff --git a/tests/api-test-2.c b/tests/api-test-2.c
index 12474fe2..3f4595fe 100644
--- a/tests/api-test-2.c
+++ b/tests/api-test-2.c
@@ -199,6 +199,11 @@ static int get_luks2_offsets(int metadata_device,
 	struct crypt_device *cd = NULL;
 	static uint64_t default_header_size = 0;
 
+	if (r_header_size)
+		*r_header_size = 0;
+	if (r_payload_offset)
+		*r_payload_offset = 0;
+
 	if (!default_header_size) {
 		if (crypt_init(&cd, THE_LOOP_DEV))
 			return -EINVAL;
@@ -966,8 +971,7 @@ static void AddDeviceLuks2(void)
 	OK_(!(global_lines != 0));
 	reset_log();
 	OK_(crypt_dump_json(cd, &tmp_buf, 0));
-	OK_(!tmp_buf);
-	OK_(!(strlen(tmp_buf) != 0));
+	OK_(!(tmp_buf && strlen(tmp_buf) != 0));
 
 	FAIL_(crypt_set_uuid(cd, "blah"), "wrong UUID format");
 	OK_(crypt_set_uuid(cd, DEVICE_TEST_UUID));
diff --git a/tests/test_utils.c b/tests/test_utils.c
index bc0bd10a..707f36a9 100644
--- a/tests/test_utils.c
+++ b/tests/test_utils.c
@@ -214,7 +214,6 @@ int get_key_dm(const char *name, char *buffer, unsigned int buffer_size)
 	struct dm_info dmi;
 	uint64_t start, length;
 	char *target_type, *key, *params;
-	void *next = NULL;
 	int r = -EINVAL;
 
 	if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
@@ -228,7 +227,7 @@ int get_key_dm(const char *name, char *buffer, unsigned int buffer_size)
 	if (!dmi.exists)
 		goto out;
 
-	next = dm_get_next_target(dmt, next, &start, &length, &target_type, &params);
+	dm_get_next_target(dmt, NULL, &start, &length, &target_type, &params);
 	if (!target_type || strcmp(target_type, "crypt") != 0)
 		goto out;