How make ally units inmune to AoE demage

[Severalser]

Hi, I'm creating a TD and some towers have splash demage, so when these tower attack the demage affect to all my towers inside the splash area. Now, someone know how I can ignore this demage?

Note: the creeps are free to attack the towers, so make invulnerable all towers is a not available solution.

 

[Nichilus]

Find the building (with splash damage) in object editor and try checking enemies/neutral in "Combat - Attack 1/2 - Area of Effect Targets"

 

[Severalser]

Thanks, it works