how to prevent this oma plata escape?

[FutureBxer]

there's this guy at our gym and everytime i get an oma plata on him, he simply falls over me(if that makes any sense. I will have his shoulder locked w/ my legs and ill be trying to grab his legs to hold him in place and he'll just roll over me. he actually put me in an oma plata with this escape before. Ive learned to avoid that but what options to you have when your opponent rolls like this?

 

[Soulfly]

Put an arm over their back to try to hold them down. If they do score the roll, wait until they are on their back, then get side control. He should be right there.

 

[DMcKayBJJ]

Keep his arm trapped, make sure you really pressure his upper back to stay where you want it to stay by keeping your leg heavy, and you GOTTA grab his belt/waist/lower body to prevent him from just rolling forward to escape.

 

[Bama Zulu]

I he rolls over YOU, then you need to stay tighter, don't let him get his right knee in because that is the main power source for the reversal.

 

[Foolkiller]

When applying the omoplata make sure the leg over his shoulder is straight so you flatten them out by putting your heel on the floor. If you don't keep your leg straight it is possible for him base up or resist. Then grab around his waist with one arm or sit up for a half nelson to finish.

 

[jamison]

Is this gi or no gi? HOLD The belt!

 

[IMP]

Rather hold the gi sleeve and trousers...

 

[Sherdog_Mutt]

What everyone else said. In addition, you can also use the momentum of his roll (if he's trying to place you in an omoplata after the roll) to do the exact same thing to him. Meaning you do the same roll as soon as he completes his roll. You'll wind up in the exact same position that you guys started out from.