diff --git a/c-programming/reverse-ramdisk.c b/c-programming/reverse-ramdisk.c
index 3756ae9..8a2c512 100644
--- a/c-programming/reverse-ramdisk.c
+++ b/c-programming/reverse-ramdisk.c
@@ -191,7 +191,7 @@ int tf_read(int ID, size_t offset, void* dest, size_t data_size) {
 } while (0)
 
 #ifdef TEST
-int main() {
+int main(void) {
 	int ID = tf_alloc(4, sizeof(int));
 	if (ID == -1)
 		retreat("tf_alloc");