*** vim/src/os_unix.c	Thu Oct 24 11:50:44 2013
--- vim-local/src/os_unix.c	Thu Oct 24 13:25:03 2013
***************
*** 804,809 ****
--- 804,815 ----
   * completely full.
   */
  
+ #if defined(__APPLE__) && \
+     defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && \
+     (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1090)
+ #include <AvailabilityMacros.h>
+ #endif
+ 
  #ifndef SIGSTKSZ
  # define SIGSTKSZ 8000    /* just a guess of how much stack is needed... */
  #endif