dh_python3 generates incorrect prerm script which cannot remove .pyc files

I use dh_python3 in python3 3.2-1.

When building deb package which uses python3 and includes only private modules, dh_python3 incorrectly inserts prerm-pyclean into the prerm scripts instead of prerm-py3clean:

============================================================
#!/bin/sh
set -e

# Automatically added by dh_python3:
if which pyclean >/dev/null 2>&1; then
 pyclean -p blender2.5
else
 dpkg -L blender2.5 | grep \.py$ | while read file
 do
  rm -f "${file}"[co] >/dev/null
   done
fi

# End automatically added section
============================================================

So, when upgrading my package using dh_python3, I got many warnings and many unnecessary .pyc files remained in my system.

I also tested python3 3.2-2 which was taken from Debian sid, and confirmed that the bug is still in the upstream latest version.

I have already reported this bug at Debian bug tracker and posted a patch.