diff --git a/tests/timestamp.c b/tests/timestamp.c
index be7dc57..dddfa6e 100644
--- a/tests/timestamp.c
+++ b/tests/timestamp.c
@@ -7,7 +7,8 @@ int main(void)
 {
 	char buffer[26];
 	time_t res = 1130620230;
-	if (Assm_tag_timestamp(buffer, sizeof(buffer), res)) printf("Time is: %s\n", buffer);
-	return EXIT_SUCCESS;
+	if (Assm_tag_timestamp(buffer, sizeof(buffer), res) && strcmp("2005-10-29T21:10:30.000Z", buffer) == 0)
+		return EXIT_SUCCESS;
+	return EXIT_FAILURE;
 }