[Orgmode] TAB character in source code blocks

[Erik Iverson]

Hello,

I'm using org source blocks to write a Makefile.

#+begin_src makefile :tangle Makefile
target: dependencies
        command
#+end_src

At least in GNU make, commands must start with a TAB.

However, after I close the code edit buffer with C-c ',
the resulting whitespace in the org-mode buffer, and thus
the tangled Makefile, is spaces and not a tab.

I haven't looked into what's causing this yet, wondering
if anyone else has come across this already and found
a solution?

Thanks,
Erik