OPLS van der waals parameters for hydrogens

Dear all,

I have a small question rather related to opls force field.
I have noticed that for all elements, except for hydrogens, opls and amber vdw parameters are similar. However, for H-atoms epsilon in vdw opls is about twice as large as vdw amber. Why does it happen? Is there a trick with treating H-atoms differently in MD simulations when using OPLS?

Best regards,