Why function template does not understand NULL but works with nullptr?

I have a function

int f(std::shared_ptr<MyClass> sptr);

After that I write the following template to be able to call it (and some other) functions:

template <typename Func, typename ArgType>
auto call(Func func, ArgType arg) -> decltype(func(arg))
{
    return func(arg);
}

Why do I get an error in the third line when I try to use this template with NULL?

auto r0 = f(0); // OK
auto r1 = call(f, nullptr); // OK
auto r2 = call(f, NULL); // ERROR! WHY??

1>------ Build started: Project: ConsoleApplication1, Configuration: Debug x64 ------
1>  main.cpp
1>main.cpp(245): error C2893: Failed to specialize function template 'unknown-type call(Func,Arg)'
1>          With the following template arguments:
1>          'Func=int (__cdecl *)(std::shared_ptr<MyClass>)'
1>          'Arg=int'
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========