make -jN parallel builds is broken

Any ideas how to fix this?

# make -j8 buildworld
--- buildworld ---
make: illegal option -- J
usage: make [-BPSXeiknpqrstv] [-C directory] [-D variable]
         [-d flags] [-E variable] [-f makefile] [-I directory]
         [-j max_jobs] [-m directory] [-V variable]
         [variable=value] [target ...]
*** [buildworld] Error code 2

make: stopped in /u/svn/commit/head4
1 error

-- 
Andre