Beyerdynamic Adjustment

I am a long time Sennheiser HD580 user and recently got a pair of DT990 to get a little more musicality.  I am very happy with sound and comfort, just got one fix I am looking for:

The size adjustment on each side always seems to slip of the spot where I want them when I take them off.  Any DT880/990 owners out there figure a way to lock these in place or make them more stiff so I don't have to adjust it every time I put them on.  Not a big deal, just be nice to not have to mess with them.