diff --git a/2021-oop1/ku/stream-03/productv2/main.cpp b/2021-oop1/ku/stream-03/productv2/main.cpp
index e278d3e26d4cb912df70b1d20c75a60a7ef8f1ad..ff1d1ca666d883b3edc6423d05ab17ba0639796f 100644
--- a/2021-oop1/ku/stream-03/productv2/main.cpp
+++ b/2021-oop1/ku/stream-03/productv2/main.cpp
@@ -1,6 +1,8 @@
 #include <cstdio>
 #include "Prod.hpp"
 
+// compile with: clang++ -std=c++17 -Wall -o prod Prod.cpp main.cpp -g
+
 int main(void)
 {
   {