In practice most compilers respect the volatile keyword on a pointer target type. But if you want to conform to the standard you need to look at what the stand

In practice most compilers respect the volatile keyword on a pointer target type. But if you want to conform to the standard you need to look at what the standard says, not merely how it's commonly implemented. §6.5.3.1/4 The unary * operator denotes indirection. (...) the result is an lvalue designating the object. Yes, but calling the sky green doesn't make it so. Dereferencing a pointer to an object yields that object, and the object is volatile or not depending on whether it was declared as volatile; whether you say that it's volatile before you dereference the pointer is irrelevant. (That is, irrelevant to the requirements of the standard; it's very relevant to most compilers, because it's usually impossible to prove whether the object ultimately being accessed is volatile or not.)