#ifndef W_OK
# ifdef OPENSSL_SYS_VMS
# include <unistd.h>
-# elif !defined(OPENSSL_SYS_VXWORKS) && !defined(OPENSSL_SYS_WINDOWS)
+# elif !defined(OPENSSL_SYS_VXWORKS) && !defined(OPENSSL_SYS_WINDOWS) && !defined(OPENSSL_SYSNAME_TANDEM)
# include <sys/file.h>
# endif
#endif