The _ctypes extension module provides dlclose on POSIX and FreeLibrary on Windows. For the reasons already stated in this issue, ctypes should not automatically call these functions, but maybe they should be documented and imported to the ctypes module instead of being buried in the private _ctypes extension module. You could also implement them with ctypes itself, but the existing functions in the _ctypes module already set a proper exception if the call fails and properly use pointers (an HMODULE is a pointer).