diff --git a/gcloud/_helpers.py b/gcloud/_helpers.py
index b60b17290180..23b66c944810 100644
--- a/gcloud/_helpers.py
+++ b/gcloud/_helpers.py
@@ -45,7 +45,7 @@
         \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}  # YYYY-MM-DDTHH:MM:SS
     )
     \.                                       # decimal point
-    (?P<nanos>\d{9})                         # nanoseconds
+    (?P<nanos>\d{1,9})                       # nanoseconds, maybe truncated
     Z                                        # Zulu
 """, re.VERBOSE)
 
@@ -344,7 +344,9 @@ def _rfc3339_nanos_to_datetime(dt_str):
                 dt_str, _RFC3339_NANOS.pattern))
     bare_seconds = datetime.datetime.strptime(
         with_nanos.group('no_fraction'), _RFC3339_NO_FRACTION)
-    nanos = int(with_nanos.group('nanos'))
+    fraction = with_nanos.group('nanos')
+    scale = 9 - len(fraction)
+    nanos = int(fraction) * (10 ** scale)
     micros = nanos // 1000
     return bare_seconds.replace(microsecond=micros, tzinfo=UTC)
 
diff --git a/gcloud/test__helpers.py b/gcloud/test__helpers.py
index fe4a8d2f4b19..6ccdb6be0b97 100644
--- a/gcloud/test__helpers.py
+++ b/gcloud/test__helpers.py
@@ -483,7 +483,9 @@ def test_w_bogus_zone(self):
         with self.assertRaises(ValueError):
             self._callFUT(dt_str)
 
-    def test_w_microseconds(self):
+    def test_w_truncated_nanos(self):
+        import datetime
+        from gcloud._helpers import UTC
 
         year = 2009
         month = 12
@@ -491,12 +493,24 @@ def test_w_microseconds(self):
         hour = 12
         minute = 44
         seconds = 32
-        micros = 123456
-
-        dt_str = '%d-%02d-%02dT%02d:%02d:%02d.%06dZ' % (
-            year, month, day, hour, minute, seconds, micros)
-        with self.assertRaises(ValueError):
-            self._callFUT(dt_str)
+        truncateds_and_micros = [
+            ('12345678', 123456),
+            ('1234567', 123456),
+            ('123456', 123456),
+            ('12345', 123450),
+            ('1234', 123400),
+            ('123', 123000),
+            ('12', 120000),
+            ('1', 100000),
+        ]
+
+        for truncated, micros in truncateds_and_micros:
+            dt_str = '%d-%02d-%02dT%02d:%02d:%02d.%sZ' % (
+                year, month, day, hour, minute, seconds, truncated)
+            result = self._callFUT(dt_str)
+            expected_result = datetime.datetime(
+                year, month, day, hour, minute, seconds, micros, UTC)
+            self.assertEqual(result, expected_result)
 
     def test_w_naonseconds(self):
         import datetime
@@ -511,7 +525,7 @@ def test_w_naonseconds(self):
         nanos = 123456789
         micros = nanos // 1000
 
-        dt_str = '%d-%02d-%02dT%02d:%02d:%02d.%06dZ' % (
+        dt_str = '%d-%02d-%02dT%02d:%02d:%02d.%09dZ' % (
             year, month, day, hour, minute, seconds, nanos)
         result = self._callFUT(dt_str)
         expected_result = datetime.datetime(