--- IO-AIO/AIO.xs	2011/01/07 21:45:42	1.178
+++ IO-AIO/AIO.xs	2011/01/07 21:47:15	1.179
@@ -639,6 +639,9 @@
 #if !_POSIX_MAPPED_FILES
 # define mmap(addr,length,prot,flags,fd,offs) (errno = ENOSYS, -1)
 # define munmap(addr,length)                  (errno = ENOSYS, -1)
+#endif
+
+#if !_POSIX_MEMORY_PROTECTION
 # define mprotect(addr,len,prot)              (errno = ENOSYS, -1)
 # define PROT_NONE   0
 # define PROT_WRITE  0