diff --git a/portalocker/__about__.py b/portalocker/__about__.py
index 3bed460..9fe427c 100644
--- a/portalocker/__about__.py
+++ b/portalocker/__about__.py
@@ -1,7 +1,7 @@
 __package_name__ = 'portalocker'
 __author__ = 'Rick van Hattem'
 __email__ = 'wolph@wol.ph'
-__version__ = '2.2.1'
+__version__ = '2.3.0'
 __description__ = '''Wraps the portalocker recipe for easy usage'''
 __url__ = 'https://github.com/WoLpH/portalocker'
 
diff --git a/portalocker/__init__.py b/portalocker/__init__.py
index b20b3d7..64b7c80 100644
--- a/portalocker/__init__.py
+++ b/portalocker/__init__.py
@@ -17,7 +17,7 @@
 #: Current author's email address
 __email__ = __about__.__email__
 #: Version number
-__version__ = '2.2.1'
+__version__ = '2.3.0'
 #: Package description for Pypi
 __description__ = __about__.__description__
 #: Package homepage
diff --git a/portalocker/py.typed b/portalocker/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/portalocker/redis.py b/portalocker/redis.py
index b2468b9..9d34b24 100644
--- a/portalocker/redis.py
+++ b/portalocker/redis.py
@@ -152,7 +152,7 @@ def acquire(
                         self.unavailable_timeout):  # pragma: no branch
                     continue
                 else:  # pragma: no cover
-                    subscribers = None
+                    subscribers = 0
 
             # Note: this should not be changed to an elif because the if
             # above can still end up here
diff --git a/portalocker/utils.py b/portalocker/utils.py
index 4226e9e..aefe299 100644
--- a/portalocker/utils.py
+++ b/portalocker/utils.py
@@ -7,11 +7,14 @@
 import tempfile
 import time
 import typing
+import logging
 
 from . import constants
 from . import exceptions
 from . import portalocker
 
+logger = logging.getLogger(__name__)
+
 DEFAULT_TIMEOUT = 5
 DEFAULT_CHECK_INTERVAL = 0.25
 DEFAULT_FAIL_WHEN_LOCKED = False
@@ -397,10 +400,9 @@ def acquire(
         assert not self.lock, 'Already locked'
 
         filenames = self.get_filenames()
-        print('filenames', filenames)
 
-        for _ in self._timeout_generator(timeout, check_interval):  # pragma:
-            print('trying lock', filenames)
+        for n in self._timeout_generator(timeout, check_interval):  # pragma:
+            logger.debug('trying lock (attempt %d) %r', n, filenames)
             # no branch
             if self.try_lock(filenames):  # pragma: no branch
                 return self.lock  # pragma: no cover
@@ -410,11 +412,11 @@ def acquire(
     def try_lock(self, filenames: typing.Sequence[Filename]) -> bool:
         filename: Filename
         for filename in filenames:
-            print('trying lock for', filename)
+            logger.debug('trying lock for %r', filename)
             self.lock = Lock(filename, fail_when_locked=True)
             try:
                 self.lock.acquire()
-                print('locked', filename)
+                logger.debug('locked %r', filename)
                 return True
             except exceptions.AlreadyLocked:
                 pass
diff --git a/setup.py b/setup.py
index 4365703..2e5c552 100644
--- a/setup.py
+++ b/setup.py
@@ -126,6 +126,7 @@ def run(self):
         author_email=about['__email__'],
         url=about['__url__'],
         license='PSF',
+        package_data=dict(portalocker=['py.typed']),
         packages=setuptools.find_packages(exclude=[
             'examples', 'portalocker_tests']),
         # zip_safe=False,