diff --git a/src/wormhole/blocking/transit.py b/src/wormhole/blocking/transit.py
index 5a8e0f5..6cf4098 100644
--- a/src/wormhole/blocking/transit.py
+++ b/src/wormhole/blocking/transit.py
@@ -202,8 +202,12 @@ class RecordPipe:
 
 class Common:
     def __init__(self, transit_relay):
-        if not isinstance(transit_relay, type(u"")): raise UsageError
-        self._transit_relay = transit_relay
+        if transit_relay:
+            if not isinstance(transit_relay, type(u"")):
+                raise UsageError
+            self._transit_relays = [transit_relay]
+        else:
+            self._transit_relays = []
         self.winning = threading.Event()
         self._negotiation_check_lock = threading.Lock()
         self._have_transit_key = threading.Condition()
@@ -224,7 +228,7 @@ class Common:
     def get_direct_hints(self):
         return self.my_direct_hints
     def get_relay_hints(self):
-        return [self._transit_relay]
+        return self._transit_relays
 
     def add_their_direct_hints(self, hints):
         for h in hints:
diff --git a/src/wormhole/test/test_scripts.py b/src/wormhole/test/test_scripts.py
index 64bf5e6..646cb03 100644
--- a/src/wormhole/test/test_scripts.py
+++ b/src/wormhole/test/test_scripts.py
@@ -85,7 +85,7 @@ class PregeneratedCode(ServerBase, ScriptsBase, unittest.TestCase):
         assert mode in ("text", "file", "directory")
         wormhole = self.find_executable()
         server_args = ["--relay-url", self.relayurl,
-                       "--transit-helper", self.transit]
+                       "--transit-helper", ""]
         code = u"1-abc"
         message = "test message"
 
diff --git a/src/wormhole/twisted/transit.py b/src/wormhole/twisted/transit.py
index 6830f8e..fc3fea5 100644
--- a/src/wormhole/twisted/transit.py
+++ b/src/wormhole/twisted/transit.py
@@ -403,9 +403,12 @@ class Common:
     RELAY_DELAY = 2.0
 
     def __init__(self, transit_relay, reactor=reactor):
-        if not isinstance(transit_relay, (type(None), type(u""))):
-            raise UsageError
-        self._transit_relay = transit_relay
+        if transit_relay:
+            if not isinstance(transit_relay, type(u"")):
+                raise UsageError
+            self._transit_relays = [transit_relay]
+        else:
+            self._transit_relays = []
         self._transit_key = None
         self._waiting_for_transit_key = []
         self._listener = None
@@ -459,9 +462,7 @@ class Common:
         self._listener_d.cancel()
 
     def get_relay_hints(self):
-        if self._transit_relay:
-            return [self._transit_relay]
-        return []
+        return self._transit_relays
 
     def add_their_direct_hints(self, hints):
         for h in hints: