Python3: Conditional extraction of keys from a dictionary with comprehension

I need to extract those keys of a dictionary whose values pass a certain condition. Basically, I want to do this, only in a shorter, more pythony way:

keys=[]
for key in dict:
    if dict[key]==True:
        keys.append(key)

This was my original idea, but it raises a ValueError:

[key for (key,val) in map if val==True]

I came up with this for the moment, but I can't help feeling it's not very nice:

[key for key in map.keys() if map[key]==True]

Is there a less messy way to it? Perhaps something obvious that I'm clearly missing?

Thanks!