Bro and jemalloc

Hi All,
i wanted to test Bro with jemalloc so i've installed the latest
version using the following commands:

git clone --recursive git://git.bro.org/bro
./configure --enable-jemalloc
make
make install

Some days later, during a check, i've found this report using the
command broctl diag

1437065570.594985 processing suspended
1437065570.594985 processing continued
src/central_freelist.cc:322] tcmalloc: allocation failed 16384
out of memory in new.
1437472834.896416 fatal error: out of memory in new.

I think that this error is due to the hardware (the testing server has
only 4GB of RAM), but i don't understand why Bro is using tcmalloc and
not jemalloc.
I've made a mistake during the compilation phase?
Thanks,
Vito