diff --git a/ChangeLog b/ChangeLog
index e0fb0abb..d2a1af41 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,8 @@
           (thanks to hosaka).
 - TI-39   Bogus command line option causes segfault
           (thanks to Jan Stolarek, Thomas Lauf).
+- TI-40   totals.py extension script fails with an error
+          (thanks to Jan Stolarek)
 - TI-42   refresh holiday script throws an error on nb-NO locale
           (thanks to Jelle van der Waa).
 - TI-47   first call successfully creates new database but returns exit status 1
@@ -20,7 +22,7 @@
           (thanks to Thomas Lauf).
 - TI-64   Command 'stop' with date before current interval's start date causes segfault
           (thanks to Thomas Lauf).
-- Fixed Python 3 support of the holdiay/refresh script
+- Fixed Python 3 support of the holiday/refresh script
           (thanks to Jelle van der Waa).
 - Added missing man page link
           (thanks to David Patrick).
diff --git a/ext/totals.py b/ext/totals.py
index a5a0a2af..fb5c2baf 100755
--- a/ext/totals.py
+++ b/ext/totals.py
@@ -60,6 +60,7 @@ for line in sys.stdin:
 
 # Sum the second tracked by tag.
 totals = dict()
+untagged = None
 j = json.loads(body)
 for object in j:
   start = datetime.datetime.strptime(object['start'], DATEFORMAT)
@@ -71,20 +72,31 @@ for object in j:
 
   tracked = end - start
 
-  for tag in object['tags']:
-    if tag in totals:
-      totals[tag] += tracked
+  if 'tags' not in object or object['tags'] == []:
+    if untagged is None:
+      untagged = tracked
     else:
-      totals[tag] = tracked
+      untagged += tracked
+  else:
+    for tag in object['tags']:
+      if tag in totals:
+        totals[tag] += tracked
+      else:
+        totals[tag] = tracked
 
 # Determine largest tag width.
-max_width = 0
+max_width = len('Total')
 for tag in totals:
   if len(tag) > max_width:
     max_width = len(tag)
 
+if 'temp.report.start' not in configuration:
+  print 'There is no data in the database'
+  exit()
+
 start = datetime.datetime.strptime(configuration['temp.report.start'], DATEFORMAT)
 end   = datetime.datetime.strptime(configuration['temp.report.end'],   DATEFORMAT)
+
 if max_width > 0:
   # Compose report header.
   print '\nTotal by Tag, for %s - %s\n' % (start, end)
@@ -103,6 +115,11 @@ if max_width > 0:
     grand_total += totals[tag].seconds
     print '%-*s %10s' % (max_width, tag, formatted)
 
+  if untagged is not None:
+    formatted = formatSeconds(untagged.seconds)
+    grand_total += untagged.seconds
+    print '%-*s %10s' % (max_width, '', formatted)
+
   # Compose total.
   if configuration['color'] == 'on':
     print ' ' * max_width, '          '
@@ -113,4 +130,3 @@ if max_width > 0:
 
 else:
   print 'No data in the range %s - %s' % (start, end)
-
diff --git a/test/test_totals.t b/test/test_totals.t
new file mode 100755
index 00000000..eba7e7f2
--- /dev/null
+++ b/test/test_totals.t
@@ -0,0 +1,80 @@
+#!/usr/bin/env python2.7
+# -*- coding: utf-8 -*-
+###############################################################################
+#
+# Copyright 2006 - 2017, Paul Beckingham, Federico Hernandez.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+# http://www.opensource.org/licenses/mit-license.php
+#
+###############################################################################
+import sys
+import os
+import subprocess
+import unittest
+# Ensure python finds the local simpletap module
+sys.path.append(os.path.dirname(os.path.abspath(__file__)))
+
+from basetest import TestCase
+
+
+class TestTotals(TestCase):
+    def setUp(self):
+        current_dir = os.path.dirname(os.path.abspath(__file__))
+        self.process = subprocess.Popen([os.path.join(current_dir, '../ext/totals.py')],
+                                        stdin=subprocess.PIPE,
+                                        stdout=subprocess.PIPE,
+                                        stderr=subprocess.PIPE)
+
+    def test_totals_with_empty_database(self):
+        """totals extension should report error on empty database"""
+        out, err = self.process.communicate(input="color: off\ndebug: on\ntemp.report.start: \ntemp.report.end: \n\n[]")
+
+        self.assertEqual('There is no data in the database\n', out)
+        self.assertEqual('', err)
+
+    def test_totals_with_filled_database(self):
+        """totals extension should print report for filled database"""
+        out, err = self.process.communicate(input="color: off\ndebug: on\ntemp.report.start: 20160101T070000Z\ntemp.report.end: 20160101T080000Z\n\n[{\"start\":\"20160101T070000Z\",\"end\":\"20160101T080000Z\",\"tags\":[\"foo\"]}]")
+
+        self.assertEqual('\nTotal by Tag, for 2016-01-01 07:00:00 - 2016-01-01 08:00:00\n\nTag        Total\n----- ----------\nfoo      1:00:00\n      ----------\nTotal    1:00:00\n', out)
+        self.assertEqual('', err)
+
+    def test_totals_with_interval_without_tags(self):
+        """totals extension should handle interval without tags"""
+        out, err = self.process.communicate(input="color: off\ndebug: on\ntemp.report.start: 20160101T070000Z\ntemp.report.end: 20160101T080000Z\n\n[{\"start\":\"20160101T070000Z\",\"end\":\"20160101T080000Z\"}]")
+
+        self.assertEqual('\nTotal by Tag, for 2016-01-01 07:00:00 - 2016-01-01 08:00:00\n\nTag        Total\n----- ----------\n         1:00:00\n      ----------\nTotal    1:00:00\n', out)
+        self.assertEqual('', err)
+
+    def test_totals_with_interval_with_empty_tag_list(self):
+        """totals extension should handle interval with empty tag list"""
+        out, err = self.process.communicate(
+            input="color: off\ndebug: on\ntemp.report.start: 20160101T070000Z\ntemp.report.end: 20160101T080000Z\n\n[{\"start\":\"20160101T070000Z\",\"end\":\"20160101T080000Z\",\"tags\":[]}]")
+
+        self.assertEqual('\nTotal by Tag, for 2016-01-01 07:00:00 - 2016-01-01 08:00:00\n\nTag        Total\n----- ----------\n         1:00:00\n      ----------\nTotal    1:00:00\n', out)
+        self.assertEqual('', err)
+
+
+if __name__ == "__main__":
+    from simpletap import TAPTestRunner
+    unittest.main(testRunner=TAPTestRunner())
+
+# vim: ai sts=4 et sw=4 ft=python