diff --git a/src/wormhole/blocking/transcribe.py b/src/wormhole/blocking/transcribe.py
index d66f5b4..88d7757 100644
--- a/src/wormhole/blocking/transcribe.py
+++ b/src/wormhole/blocking/transcribe.py
@@ -135,7 +135,10 @@ class ChannelManager:
         r = requests.get(self._relay_url+"list?%s" % queryargs,
                          timeout=self._timeout)
         r.raise_for_status()
-        channelids = r.json()["channelids"]
+        data = r.json()
+        if "welcome" in data:
+            self._handle_welcome(data["welcome"])
+        channelids = data["channelids"]
         return channelids
 
     def allocate(self):
@@ -241,7 +244,12 @@ class Wormhole:
 
     def input_code(self, prompt="Enter wormhole code: ", code_length=2):
         lister = self._channel_manager.list_channels
-        code = codes.input_code_with_completion(prompt, lister,
+        # fetch the list of channels ahead of time, to give us a chance to
+        # discover the welcome message (and warn the user about an obsolete
+        # client)
+        initial_channelids = lister()
+        code = codes.input_code_with_completion(prompt,
+                                                initial_channelids, lister,
                                                 code_length)
         return code
 
diff --git a/src/wormhole/codes.py b/src/wormhole/codes.py
index 0a49890..3b1ff79 100644
--- a/src/wormhole/codes.py
+++ b/src/wormhole/codes.py
@@ -21,12 +21,20 @@ import readline
 #import sys
 
 class CodeInputter:
-    def __init__(self, get_channel_ids, code_length):
-        self.get_channel_ids = get_channel_ids
+    def __init__(self, initial_channelids, get_channel_ids, code_length):
+        self._initial_channelids = initial_channelids
+        self._get_channel_ids = get_channel_ids
         self.code_length = code_length
         self.last_text = None # memoize for a speedup
         self.last_matches = None
 
+    def get_current_channel_ids(self):
+        if self._initial_channelids is not None:
+            channelids = self._initial_channelids
+            self._initial_channelids = None
+            return channelids
+        return self._get_channel_ids()
+
     def wrap_completer(self, text, state):
         try:
             return self.completer(text, state)
@@ -52,7 +60,7 @@ class CodeInputter:
             #print(" old matches", len(matches), file=sys.stderr)
         else:
             if len(pieces) <= 1:
-                channel_ids = self.get_channel_ids()
+                channel_ids = self.get_current_channel_ids()
                 matches = [str(channel_id) for channel_id in channel_ids
                            if str(channel_id).startswith(last)]
             else:
@@ -76,8 +84,9 @@ class CodeInputter:
         return match
 
 
-def input_code_with_completion(prompt, get_channel_ids, code_length):
-    c = CodeInputter(get_channel_ids, code_length)
+def input_code_with_completion(prompt, initial_channelids, get_channel_ids,
+                               code_length):
+    c = CodeInputter(initial_channelids, get_channel_ids, code_length)
     readline.parse_and_bind("tab: complete")
     readline.set_completer(c.wrap_completer)
     readline.set_completer_delims("")