#include <boost/shared_ptr.hpp>
#include <boost/signal.hpp>
-#include <sys/types.h>
-
-// pid_t isn't defined by the stdlibs that ship with MSVC.
-#if defined (_WIN32) && defined(_MSC_VER)
-typedef int pid_t;
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
#endif