diff --git a/bookwyrm/connectors/connector_manager.py b/bookwyrm/connectors/connector_manager.py
index 3891d02a..3ed25ceb 100644
--- a/bookwyrm/connectors/connector_manager.py
+++ b/bookwyrm/connectors/connector_manager.py
@@ -18,7 +18,7 @@ def search(query, min_confidence=0.1):
     results = []
 
     # Have we got a ISBN ?
-    isbn = re.sub("[\W_]", "", query)
+    isbn = re.sub(r"[\W_]", "", query)
     maybe_isbn = len(isbn) in [10, 13]  # ISBN10 or ISBN13
 
     dedup_slug = lambda r: "%s/%s/%s" % (r.title, r.author, r.year)
@@ -36,7 +36,7 @@ def search(query, min_confidence=0.1):
                     pass
 
         # if no isbn search or results, we fallback to generic search
-        if result_set == None or result_set == []:
+        if result_set in (None, []):
             try:
                 result_set = connector.search(query, min_confidence=min_confidence)
             except (HTTPError, ConnectorException):
diff --git a/bookwyrm/tests/connectors/test_connector_manager.py b/bookwyrm/tests/connectors/test_connector_manager.py
index 4410e011..52589323 100644
--- a/bookwyrm/tests/connectors/test_connector_manager.py
+++ b/bookwyrm/tests/connectors/test_connector_manager.py
@@ -15,7 +15,7 @@ class ConnectorManager(TestCase):
         self.work = models.Work.objects.create(title="Example Work")
 
         self.edition = models.Edition.objects.create(
-            title="Example Edition", parent_work=self.work
+            title="Example Edition", parent_work=self.work, isbn_10="0000000000"
         )
         self.work.default_edition = self.edition
         self.work.save()
@@ -28,6 +28,7 @@ class ConnectorManager(TestCase):
             base_url="http://test.com/",
             books_url="http://test.com/",
             covers_url="http://test.com/",
+            isbn_search_url="http://test.com/isbn/",
         )
 
     def test_get_or_create_connector(self):
@@ -58,6 +59,14 @@ class ConnectorManager(TestCase):
         self.assertEqual(len(results[0]["results"]), 1)
         self.assertEqual(results[0]["results"][0].title, "Example Edition")
 
+    def test_search_isbn(self):
+        """ special handling if a query resembles an isbn """
+        results = connector_manager.search("0000000000")
+        self.assertEqual(len(results), 1)
+        self.assertIsInstance(results[0]["connector"], SelfConnector)
+        self.assertEqual(len(results[0]["results"]), 1)
+        self.assertEqual(results[0]["results"][0].title, "Example Edition")
+
     def test_local_search(self):
         """ search only the local database """
         results = connector_manager.local_search("Example")