Does mispronunciation after ruku invalidate salat?

I was praying fajr and I accidentally said "rabbana wa lakan hamd" instead of "rabbana wa lakal hamd". Is my prayer valid? I heard that mispronunciation in fatiha can invalidate salah, but what is the ruling here? I am not a native arabic speaker and I didn’t really correct my mistake, although I did notice it after I said it.