diff --git a/chkcrontab b/chkcrontab
index 3ad4291..513ed10 100755
--- a/chkcrontab
+++ b/chkcrontab
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 #
 # Copyright 2011 Google Inc. All Rights Reserved.
 #
@@ -31,21 +31,19 @@ import chkcrontab_lib as check
 
 from optparse import OptionParser
 from argparse import ArgumentParser
-try:
-  from _version import __version__
-except ImportError:
-  __version__ = 'unknown'
 
 def main(argv):
   """main program."""
   parser = ArgumentParser(
       description='Parse crontab files; check for potential syntax errors.',
-      version=__version__)
+      )
   parser.add_argument('crontab', help='crontab file to parse')
   parser.add_argument('-w', '--whitelist', action='append',
       dest='whitelisted_users',
       help='user to ignore when warning of unrecognized users; may be passed multiple times',
       default=['postgres', 'buildbot'])
+  parser.add_argument('-u', '--user', action='store_true',
+      dest='user', help='crontab user')
   parser.add_argument('-n', '--no-check-passwd', action='store_false',
       dest='check_passwd', help='disable user lookup')
   parser.add_argument('-q', '--quiet', action='store_true',
@@ -57,4 +55,5 @@ def main(argv):
   return check.check_crontab(args, check.LogCounter(args.quiet))
 
 if __name__ == '__main__':
-  sys.exit(main(sys.argv))
+  main(sys.argv)
+  sys.exit(0)
diff --git a/chkcrontab_lib.py b/chkcrontab_lib.py
index 344dbd7..bfe56c8 100755
--- a/chkcrontab_lib.py
+++ b/chkcrontab_lib.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 #
 # Copyright 2011 Google Inc. All Rights Reserved.
 #
@@ -716,6 +716,8 @@ def ValidateAndLog(self, log):
     # User checks.
     if self.user in self.whitelisted_users:
       pass
+    elif self.user is False:
+      pass
     elif len(self.user) > 31:
       log.LineError(log.MSG_INVALID_USER,
                     'Username too long "%s"' % self.user)
@@ -806,7 +808,8 @@ def ValidateAndLog(self, log):
 class CronLineFactory(object):
   """Classify a line in a cron field by what type of line it is."""
 
-  def __init__(self):
+  def __init__(self, is_user_crontab=False):
+    self.is_user_crontab = is_user_crontab
     pass
 
   def ParseLine(self, line, options ):
@@ -819,14 +822,20 @@ def ParseLine(self, line, options ):
     Returns:
       A CronLine* class (must have a ValidateAndLog method).
     """
-    chkcrontab_cmd = re.compile('##*\s*chkcrontab:\s*(.*)=(.*)')
-    assignment_line_re = re.compile('[a-zA-Z_][a-zA-Z0-9_]*\s*=(.*)')
-    at_line_re = re.compile('@(\S+)\s+(\S+)\s+(.*)')
-    cron_time_field_re = '[\*0-9a-zA-Z,/-]+'
-    time_field_job_line_re = re.compile(
-        '^\s*(%s)\s+(%s)\s+(%s)\s+(%s)\s+(%s)\s+(\S+)\s+(.*)' %
-        (cron_time_field_re, cron_time_field_re, cron_time_field_re,
-         cron_time_field_re, cron_time_field_re))
+    chkcrontab_cmd = re.compile(r'##*\s*chkcrontab:\s*(.*)=(.*)')
+    assignment_line_re = re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*\s*=(.*)')
+    at_line_re = re.compile(r'@(\S+)\s+(\S+)\s+(.*)')
+    cron_time_field_re = r'[\*0-9a-zA-Z,/-]+'
+    if self.is_user_crontab:
+        time_field_job_line_re = re.compile(
+            r'^\s*(%s)\s+(%s)\s+(%s)\s+(%s)\s+(%s)\s+(.*)' %
+            (cron_time_field_re, cron_time_field_re, cron_time_field_re,
+             cron_time_field_re, cron_time_field_re))
+    else:
+        time_field_job_line_re = re.compile(
+            r'^\s*(%s)\s+(%s)\s+(%s)\s+(%s)\s+(%s)\s+(\S+)\s+(.*)' %
+            (cron_time_field_re, cron_time_field_re, cron_time_field_re,
+             cron_time_field_re, cron_time_field_re))
 
     if not line:
       return CronLineEmpty()
@@ -857,7 +866,10 @@ def ParseLine(self, line, options ):
           'month': match.groups()[3],
           'day of week': match.groups()[4],
           }
-      return CronLineTime(field, match.groups()[5], match.groups()[6], options)
+      if self.is_user_crontab:
+          return CronLineTime(field, False, match.groups()[5], options)
+      else:
+          return CronLineTime(field, match.groups()[5], match.groups()[6], options)
 
     return CronLineUnknown()
 
@@ -1100,7 +1112,7 @@ def check_crontab(arguments, log):
                ' [A-Za-z0-9_-]+ .')
 
   line_no = 0
-  cron_line_factory = CronLineFactory()
+  cron_line_factory = CronLineFactory(arguments.user)
   with open(arguments.crontab, 'r') as crontab_f:
     for line in crontab_f:
       missing_newline = line[-1] != "\n"
diff --git a/tests/test_check.py b/tests/test_check.py
index 642f7fc..930a48d 100755
--- a/tests/test_check.py
+++ b/tests/test_check.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 #
 # Copyright 2011 Google Inc. All Rights Reserved.
 #