diff --git a/kgb/__init__.py b/kgb/__init__.py
index ced63a0108ba69cd814467960d3587514b7dadd8..4fd8c4b16adec109514d80bef784cac119de05f1 100644
--- a/kgb/__init__.py
+++ b/kgb/__init__.py
@@ -20,6 +20,12 @@ VERSION = (7, 0, 0, 'alpha', 0, False)
 
 
 def get_version_string():
+    """Return the kgb version as a human-readable string.
+
+    Returns:
+        unicode:
+        The kgb version.
+    """
     version = '%s.%s' % (VERSION[0], VERSION[1])
 
     if VERSION[2]:
@@ -38,18 +44,38 @@ def get_version_string():
 
 
 def get_package_version():
+    """Return the kgb version as a Python package version string.
+
+    Returns:
+        unicode:
+        The kgb package version.
+    """
     version = '%s.%s' % (VERSION[0], VERSION[1])
 
     if VERSION[2]:
-        version += ".%s" % VERSION[2]
+        version += '.%s' % VERSION[2]
 
-    if VERSION[3] != 'final':
-        version += '%s%s' % (VERSION[3], VERSION[4])
+    tag = VERSION[3]
+
+    if tag != 'final':
+        if tag == 'alpha':
+            tag = 'a'
+        elif tag == 'beta':
+            tag = 'b'
+
+        version = '%s%s%s' % (version, tag, VERSION[4])
 
     return version
 
 
 def is_release():
+    """Return whether this is a released version of kgb.
+
+    Returns:
+        bool:
+        ``True`` if the version is released. ``False`` if it is still in
+        development.
+    """
     return VERSION[5]
 
 
diff --git a/setup.py b/setup.py
index e50fcda7e8c526bde569e8eb5658adaf21010486..eed0d9b3b5bf56bede7b2ddc68f1ff48acd71573 100755
--- a/setup.py
+++ b/setup.py
@@ -49,6 +49,15 @@ setup(name=PACKAGE_NAME,
       packages=find_packages(),
       maintainer='Christian Hammond',
       maintainer_email='christian@beanbaginc.com',
+      python_requires=','.join([
+          '>=2.7',
+          '!=3.0.*',
+          '!=3.1.*',
+          '!=3.2.*',
+          '!=3.3.*',
+          '!=3.4.*',
+          '!=3.5.*',
+      ]),
       classifiers=[
           'Development Status :: 5 - Production/Stable',
           'Environment :: Other Environment',