diff --git a/CHANGES.txt b/CHANGES.txt
index cea315b..21af8c1 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -4,6 +4,8 @@ Unreleased
 Features
 ~~~~~~~~
 
+- Support spec-mandated truncations of ISO-8601 timezones.
+
 - Support spec-mandated truncations of ISO-8601 datetimes.
 
 - Allow specifying custom representations of values for boolean fields.
diff --git a/colander/iso8601.py b/colander/iso8601.py
index d2c89b4..6c74aae 100644
--- a/colander/iso8601.py
+++ b/colander/iso8601.py
@@ -41,10 +41,10 @@ __all__ = ["parse_date", "ParseError", "Utc", "FixedOffset"]
 ISO8601_REGEX = re.compile(
     r"(?P<year>[0-9]{4})(-(?P<month>[0-9]{1,2})(-(?P<day>[0-9]{1,2})"
     r"((?P<separator>.)(?P<hour>[0-9]{2})(:(?P<minute>[0-9]{2})(:(?P<second>[0-9]{2})(\.(?P<fraction>[0-9]+))?)?)?"
-    r"(?P<timezone>Z|(([-+])([0-9]{2}):([0-9]{2})))?)?)?)?"
+    r"(?P<timezone>Z|(([-+])([0-9]{2})(:?([0-9]{2}))?))?)?)?)?"
 )
 TIMEZONE_REGEX = re.compile(
-    "(?P<prefix>[+-])(?P<hours>[0-9]{2}).(?P<minutes>[0-9]{2})")
+    "(?P<prefix>[+-])(?P<hours>[0-9]{2})(:?(?P<minutes>[0-9]{2}))?")
 
 class ParseError(Exception):
     """Raised when there is a problem parsing a date string"""
@@ -97,8 +97,13 @@ def parse_timezone(tzstring, default_timezone=UTC):
     if tzstring is None:
         return default_timezone
     m = TIMEZONE_REGEX.match(tzstring)
-    prefix, hours, minutes = m.groups()
-    hours, minutes = int(hours), int(minutes)
+    prefix = m.group('prefix')
+    hours = int(m.group('hours'))
+    minutes = m.group('minutes')
+    if minutes is None:
+        minutes = 0
+    else:
+        minutes = int(minutes)
     if prefix == "-":
         hours = -hours
         minutes = -minutes
diff --git a/colander/tests/test_iso8601.py b/colander/tests/test_iso8601.py
index a8b5de7..95501ee 100644
--- a/colander/tests/test_iso8601.py
+++ b/colander/tests/test_iso8601.py
@@ -70,12 +70,36 @@ class Test_parse_timezone(unittest.TestCase):
         self.assertEqual(result.utcoffset(None),
                          datetime.timedelta(hours=1, minutes=0))
 
+    def test_positive_without_colon(self):
+        tzstring = "+0100"
+        result = self._callFUT(tzstring)
+        self.assertEqual(result.utcoffset(None),
+                         datetime.timedelta(hours=1, minutes=0))
+
+    def test_positive_without_minutes(self):
+        tzstring = "+01"
+        result = self._callFUT(tzstring)
+        self.assertEqual(result.utcoffset(None),
+                         datetime.timedelta(hours=1, minutes=0))
+
     def test_negative(self):
         tzstring = "-01:00"
         result = self._callFUT(tzstring)
         self.assertEqual(result.utcoffset(None),
                          datetime.timedelta(hours=-1, minutes=0))
 
+    def test_negative_without_colon(self):
+        tzstring = "-0100"
+        result = self._callFUT(tzstring)
+        self.assertEqual(result.utcoffset(None),
+                         datetime.timedelta(hours=-1, minutes=0))
+
+    def test_negative_without_minutes(self):
+        tzstring = "-01"
+        result = self._callFUT(tzstring)
+        self.assertEqual(result.utcoffset(None),
+                         datetime.timedelta(hours=-1, minutes=0))
+
 class Test_parse_date(unittest.TestCase):
     def _callFUT(self, datestring):
         from ..iso8601 import parse_date