Dependency on lib32foo vs libfoo on amd64

[Igor Pashev <pashev.igor@gmail.com>]

I'm building a package with:

64-bits app (foo),
64-bits lib (libfoo) and
32-bits lib (lib32foo).

foo is linked with libfoo, but dependency in DEBIAN/control
is set to li32foo.

What's the matter?

dpkg 1.16.1
DH 8.9.8