Org writer: wrong indentation of properties block

When typing either
echo "<h2>Title</h2>" | pandoc -f html -t org
or
echo "** Title" | pandoc -f org -t org
Pandoc produces

** Title
   :PROPERTIES:
   :CUSTOM_ID: title
   :END:

The properties block shouldn't be aligned to the title but rather start at column 0:

** Title
:PROPERTIES:
:CUSTOM_ID: title
:END:

I'm using a fresh version of Pandoc built from trunk.

Provide feedback