A Japanese news outlet is reporting that North Korean missile technicians helped Iran launch a satellite last month.

Quoting a source familiar with Korean peninsular affairs, Japan’s Sankei Shimbun reported that North Korean missile experts were heavily involved in the Iranian satellite launch.

According to the Japanese daily, the North received test data from Iran as compensation and will likely use the information should Pyongyang test-fire its Daepodong Two long-range ballistic missile.

Sankei noted that the North’s Daepodong Two has a similar propulsion system to that of Iran’s home-grown Safir Two rocket, which was used for the satellite launch. The two also run on the same type of liquid fuel.

Iran successfully launched its “Omid” satellite early last month.