Really? I've never had that problem. Smok products are my fave. I have the TFV4 and the TF-RTA. Both have that hinging top. Never had a problem with it accidentally opening. Do you keep that white stopper/drip guard in it? The one that goes right under the lid? I think that plays a part. If you take it out shyt isn't as tight.lets just say they are not clutz proof. they are nice but you have to be vigilant with them. for example both my brother and i have had the lids come open in our pocket