diff --git a/patchwork/parser.py b/patchwork/parser.py
index 0e88d934..45930b45 100644
--- a/patchwork/parser.py
+++ b/patchwork/parser.py
@@ -250,14 +250,32 @@ def _find_series_by_references(project, mail):
     Returns:
         The matching ``Series`` instance, if any
     """
+    subject = mail.get('Subject')
+    name, prefixes = clean_subject(subject, [project.linkname])
+    version = parse_version(name, prefixes)
+
     refs = find_references(mail)
     h = clean_header(mail.get('Message-Id'))
     if h:
         refs = [h] + refs
+
     for ref in refs:
         try:
             series = SeriesReference.objects.get(
                 msgid=ref[:255], project=project).series
+
+            if series.version != version:
+                # if the versions don't match, at least make sure these were
+                # sent around the same time
+                date = find_date(mail)
+                delta = datetime.timedelta(minutes=SERIES_DELAY_INTERVAL)
+                start_date = date - delta
+                end_date = date + delta
+
+                # ...and if they don't, this probably isn't our series
+                if start_date > series.date > end_date:
+                    continue
+
             # we want to return a queryset like '_find_series_by_markers'
             return Series.objects.filter(id=series.id)
         except SeriesReference.DoesNotExist:
diff --git a/patchwork/tests/series/bugs-mixed-versions.mbox b/patchwork/tests/series/bugs-mixed-versions.mbox
new file mode 100644
index 00000000..1aa639be
--- /dev/null
+++ b/patchwork/tests/series/bugs-mixed-versions.mbox
@@ -0,0 +1,110 @@
+From stephenfinucane@gmail.com Sun Sep 11 23:22:13 2016
+Return-Path: <stephenfinucane@gmail.com>
+From: Stephen Finucane <stephenfinucane@gmail.com>
+To: stephenfinucane@hotmail.com
+Subject: [PATCH 1/2] test: Add some lorem ipsum
+Date: Sun, 11 Sep 2016 23:22:03 +0100
+Message-ID: <1473632524-8585-2-git-send-email-stephenfinucane@gmail.com>
+X-Mailer: git-send-email 2.7.4
+MIME-Version: 1.0
+Content-Type: text/plain
+Content-Length: 670
+Lines: 22
+
+From: Stephen Finucane <stephenfinucane@hotmail.com>
+
+---
+ test.txt | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/test.txt b/test.txt
+index f75ba05..a6c61c0 100644
+--- a/test.txt
++++ b/test.txt
+@@ -1 +1,8 @@
+ Hello, world.
++
++Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras eget eleifend
++augue. Nullam at metus venenatis, laoreet neque nec, convallis mauris.
++Pellentesque aliquam at nisi et laoreet. Duis non nisl venenatis, rhoncus risus
++id, elementum felis. In hac habitasse platea dictumst. Nam sit amet maximus
++eros. Nam quis ligula ut tortor egestas bibendum. Nunc sed purus sit amet
++tellus commodo bibendum ut vel dolor.
+-- 
+2.7.4
+
+
+From stephenfinucane@gmail.com Sun Sep 18 23:31:07 2016
+Return-Path: <stephenfinucane@gmail.com>
+From: Stephen Finucane <stephenfinucane@gmail.com>
+To: stephenfinucane@hotmail.com
+Subject: [PATCH v2 2/2] test: Convert to Markdown
+Date: Sun, 18 Sep 2016 23:30:55 +0100
+Message-ID: <1473633055-10316-3-git-send-email-stephenfinucane@gmail.com>
+X-Mailer: git-send-email 2.7.4
+In-Reply-To: <1473633055-10316-2-git-send-email-stephenfinucane@gmail.com>
+References: <1473633055-10316-2-git-send-email-stephenfinucane@gmail.com>
+MIME-Version: 1.0
+Content-Type: text/plain
+Content-Length: 2589
+Lines: 58
+
+From: Stephen Finucane <stephenfinucane@hotmail.com>
+
+---
+ test.md  | 17 +++++++++++++++++
+ test.txt | 17 -----------------
+ 2 files changed, 17 insertions(+), 17 deletions(-)
+ create mode 100644 test.md
+ delete mode 100644 test.txt
+
+diff --git a/test.md b/test.md
+new file mode 100644
+index 0000000..201bfe7
+--- /dev/null
++++ b/test.md
+@@ -0,0 +1,17 @@
++# Hello, world
++
++Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras eget eleifend
++augue. Nullam at metus venenatis, laoreet neque nec, convallis mauris.
++Pellentesque aliquam at nisi et laoreet. Duis non nisl venenatis, rhoncus risus
++id, elementum felis. In hac habitasse platea dictumst. Nam sit amet maximus
++eros. Nam quis ligula ut tortor egestas bibendum. Nunc sed purus sit amet
++tellus commodo bibendum ut vel dolor.
++
++Curabitur scelerisque tempus efficitur. Maecenas aliquet elementum quam, ac
++pharetra nisi gravida a. Nam vitae malesuada leo. Nam accumsan facilisis metus
++sed vulputate. Ut libero odio, tempor ac posuere vel, malesuada quis ex. Donec
++interdum ipsum et nibh molestie auctor eget in neque. Sed nec hendrerit enim.
++Etiam scelerisque non magna eu molestie. Maecenas dui quam, tempor quis ipsum
++eu, dapibus congue dui. Integer tincidunt accumsan tortor sed maximus. Praesent
++eu magna accumsan, consequat turpis quis, fringilla ante. Vestibulum nec
++maximus nulla. Donec vehicula nisl at pharetra eleifend.
+diff --git a/test.txt b/test.txt
+deleted file mode 100644
+index 4478ac2..0000000
+--- a/test.txt
++++ /dev/null
+@@ -1,17 +0,0 @@
+-Hello, world.
+-
+-Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras eget eleifend
+-augue. Nullam at metus venenatis, laoreet neque nec, convallis mauris.
+-Pellentesque aliquam at nisi et laoreet. Duis non nisl venenatis, rhoncus risus
+-id, elementum felis. In hac habitasse platea dictumst. Nam sit amet maximus
+-eros. Nam quis ligula ut tortor egestas bibendum. Nunc sed purus sit amet
+-tellus commodo bibendum ut vel dolor.
+-
+-Curabitur scelerisque tempus efficitur. Maecenas aliquet elementum quam, ac
+-pharetra nisi gravida a. Nam vitae malesuada leo. Nam accumsan facilisis metus
+-sed vulputate. Ut libero odio, tempor ac posuere vel, malesuada quis ex. Donec
+-interdum ipsum et nibh molestie auctor eget in neque. Sed nec hendrerit enim.
+-Etiam scelerisque non magna eu molestie. Maecenas dui quam, tempor quis ipsum
+-eu, dapibus congue dui. Integer tincidunt accumsan tortor sed maximus. Praesent
+-eu magna accumsan, consequat turpis quis, fringilla ante. Vestibulum nec
+-maximus nulla. Donec vehicula nisl at pharetra eleifend.
+-- 
+2.7.4
+
+
diff --git a/patchwork/tests/test_series.py b/patchwork/tests/test_series.py
index 295a049d..2e86e47c 100644
--- a/patchwork/tests/test_series.py
+++ b/patchwork/tests/test_series.py
@@ -538,6 +538,23 @@ class RevisedSeriesTest(_BaseTestCase):
 
         self.assertSerialized(patches, [1, 1, 1])
 
+    def test_mixed_versions(self):
+        """Series with a revision sent in reply to an incompleted series.
+
+        Parse a series with two patches, one of which has been lost or
+        miscategorized, followed by a second revision of the missing patch.
+        None of the patches of the second revision should be included in the
+        first revision.
+
+          - [PATCH 1/2] test: Add some lorem ipsum
+            - [PATCH v2 2/2] test: Convert to Markdown
+        """
+        _, patches, _ = self._parse_mbox(
+            'bugs-mixed-versions.mbox', [0, 2, 0],
+        )
+
+        self.assertSerialized(patches, [1, 1])
+
 
 class SeriesTotalTest(_BaseTestCase):
 
