diff --git a/src/python/dm/common/exceptions/invalidSession.py b/src/python/dm/common/exceptions/invalidSession.py
index 420bbda2229c644f342c51581b17ace9cc913555..fd6b029b7cc38fd70e7294553c04fc2957ae978b 100755
--- a/src/python/dm/common/exceptions/invalidSession.py
+++ b/src/python/dm/common/exceptions/invalidSession.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 
 #
-# Invalid request error class.
+# Invalid session error class.
 #
 
 #######################################################################
@@ -11,6 +11,6 @@ from dm.common.exceptions.dmException import DmException
 
 #######################################################################
 
-class InvalidRequest(DmException):
+class InvalidSession(DmException):
     def __init__ (self, error='', **kwargs):
         DmException.__init__(self, error, dmStatus.DM_INVALID_SESSION, **kwargs)
diff --git a/src/python/dm/common/service/loginController.py b/src/python/dm/common/service/loginController.py
index 62a4c2a86f3161bab4c14984d3fca8f27fa880a1..662957a9a8a1a2e505f0ae5d81fd176e1dbe64f5 100755
--- a/src/python/dm/common/service/loginController.py
+++ b/src/python/dm/common/service/loginController.py
@@ -10,6 +10,7 @@ from dm.common.constants import dmHttpStatus
 from dm.common.exceptions.dmException import DmException
 from dm.common.exceptions.dmHttpError import DmHttpError
 from dm.common.exceptions.authorizationError import AuthorizationError
+from dm.common.exceptions.invalidSession import InvalidSession
 from dm.common.utility.loggingManager import LoggingManager
 from dm.common.service.dmController import DmController
 from dm.common.service.auth.authorizationPrincipalManager import AuthorizationPrincipalManager
@@ -135,7 +136,7 @@ class LoginController(DmController):
         if not sessionCache.has_key(sessionId):
             errorMsg = 'Invalid or expired session id: %s.' % sessionId
             logger.debug(errorMsg)
-            raise DmHttpError(dmHttpStatus.DM_HTTP_UNAUTHORIZED, 'User Not Authorized', AuthorizationError(errorMsg))
+            raise DmHttpError(dmHttpStatus.DM_HTTP_UNAUTHORIZED, 'User Not Authorized', InvalidSession(errorMsg))
 
         username = cherrypy.session.get(LoginController.SESSION_USERNAME_KEY)
         logger.debug('Session id %s is valid (username: %s)' % (sessionId, username))