diff --git a/README b/README
index 04faf72..909d13d 100644
--- a/README
+++ b/README
@@ -215,3 +215,5 @@ v1.6 UMBREON
 * figure out how to parse ssh.com encrypted key files?
 * is it possible to poll on a set of events at once?
 * potentially create only one thread shared by all Transports
+* SSHClient: flag to turn off agent detection? flag to turn off keyfile discovery?
+
diff --git a/paramiko/__init__.py b/paramiko/__init__.py
index 65f2820..94565d9 100644
--- a/paramiko/__init__.py
+++ b/paramiko/__init__.py
@@ -96,6 +96,7 @@ for c in locals().values():
     if issubclass(type(c), type) or type(c).__name__ == 'classobj':
         # classobj for exceptions :/
         c.__module__ = __name__
+del c
 
 from common import AUTH_SUCCESSFUL, AUTH_PARTIALLY_SUCCESSFUL, AUTH_FAILED, \
      OPEN_SUCCEEDED, OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED,  OPEN_FAILED_CONNECT_FAILED, \
@@ -112,6 +113,7 @@ __all__ = [ 'Transport',
             'SecurityOptions',
             'SubsystemHandler',
             'Channel',
+            'PKey',
             'RSAKey',
             'DSSKey',
             'Message',