Minecraft: Prevent Spawnen from Enderman?

So I'm playing Minecraft now and then, but I've just arrived at a small problem:

I'm currently building a small Enderman farm in the end and have the problem that the critters now spawn on the roof.

This is bad because the Killen one directly when you leave the farm then.

Does anybody know how to stop this?

Thanks in advance

PS: No mods or commands suggest, rip on a server

You can plaster the whole with carpets or half steps:-)

Maybe build the roof higher.

Ok, thanks, I'll try ^^

Simply illuminate the roof with torches or other bulbs.

The Enderman and other monsters spawn only at a light level of 7 or less. A torch has a light level of 14, so you can illuminate 13x13x13 blocks.

You can also use half-steps or make a half-open roof over it, which is sometimes only 2 blocks high. They can't spawn either.

I could do it but it should look good

Ok, thanks, I will try out directly

Alternatively: place water. Endermans do not like water in Minecraft!