Fix extra points issue

Some events cause an explosion object to be generated, which will give the player points when it overlaps with a target. Sometimes, there's an issue, and it causes more points than there should be. Is there a way to fix this? This is my Construct code:

Explode: is overlapping target --> Target:destroy. System: Add 10 to score.

Is overlapping runs constantly. So either use on collision, which triggers just once, or use the system condition trigger once while true as a sub condition, with the add 10.