Later in 2011 he was promoted to under-17 side, being called-up by manager Džemal Mustedanagić for the qualifying games of 2012 UEFA European Under-17 Championship in October. He made his first appearance for the team in the opening qualifying match versus Slovakia, coming on as a late replacement for Frans Ymeralilaj, who had given Albania the win thanks to his brace. He went on to play another against Estonia which ended in a 1–1; this result secured Albania a place in the elite round of the European Championship for the first time in 9 seasons. In the elite round, Vatnikaj continued to be a substitute, appearing only in the last minutes as Albania was eliminated after finished 3rd in Group 5.