Confused by behavior of standard_library.suspend_hooks()

[bjmc]

If I have the following...

module1.py:

from future import standard_library
standard_library.install_aliases()

with standard_library.suspend_hooks():
  import module2

and module2.py:

from __future__ import print_function

try:
    from urllib.parse import urljoin
except ImportError:
    from urlparse import urljoin
    print("Python2-style import")
else:
    print("Python3-style import")

If I run $ python module1.py I was expecting to see 'Python2-style import', but instead I'm getting 'Python3-style import'.

Is there something I'm misunderstanding about the suspend_hooks() context manager? From the documentation, I assumed it would disable the Python3-style standard library imports so that imported libraries that break under monkeypatching will get the normal, Python2 libraries.