diff --git a/src/wormhole/transcribe.py b/src/wormhole/transcribe.py
index e588198..8aef09b 100644
--- a/src/wormhole/transcribe.py
+++ b/src/wormhole/transcribe.py
@@ -17,7 +17,21 @@ class Timeout(Exception):
 # POST /CHANNEL-ID/SIDE/data/poll                 -> {messages: [STR..]}
 # POST /CHANNEL-ID/SIDE/deallocate                -> waiting | deleted
 
-class Initiator:
+class Common:
+    def url(self, suffix):
+        return "%s%d/%s/%s" % (self.relay, self.channel_id, self.side, suffix)
+
+    def poll(self, msgs, url_suffix):
+        while not msgs:
+            if time.time() > (self.started + self.timeout):
+                raise Timeout
+            time.sleep(self.wait)
+            r = requests.post(self.url(url_suffix))
+            r.raise_for_status()
+            msgs = r.json()["messages"]
+        return msgs
+
+class Initiator(Common):
     def __init__(self, appid, data, relay=RELAY):
         self.appid = appid
         self.data = data
@@ -28,9 +42,6 @@ class Initiator:
         self.timeout = 3*MINUTE
         self.side = "initiator"
 
-    def url(self, suffix):
-        return "%s%d/%s/%s" % (self.relay, self.channel_id, self.side, suffix)
-
     def get_code(self):
         # allocate channel
         r = requests.post(self.relay + "allocate")
@@ -48,15 +59,7 @@ class Initiator:
 
     def get_data(self):
         # poll for PAKE response
-        while True:
-            r = requests.post(self.url("pake/poll"))
-            r.raise_for_status()
-            msgs = r.json()["messages"]
-            if msgs:
-                break
-            if time.time() > (self.started + self.timeout):
-                raise Timeout
-            time.sleep(self.wait)
+        msgs = self.poll([], "pake/poll")
         pake_msg = unhexlify(msgs[0].encode("ascii"))
         self.key = self.sp.finish(pake_msg)
 
@@ -64,17 +67,10 @@ class Initiator:
         post_data = json.dumps({"message": hexlify(self.data).decode("ascii")})
         r = requests.post(self.url("data/post"), data=post_data)
         r.raise_for_status()
+        other_msgs = r.json()["messages"]
 
         # poll for data message
-        while True:
-            r = requests.post(self.url("data/poll"))
-            r.raise_for_status()
-            msgs = r.json()["messages"]
-            if msgs:
-                break
-            if time.time() > (self.started + self.timeout):
-                raise Timeout
-            time.sleep(self.wait)
+        msgs = self.poll(other_msgs, "data/poll")
         data = unhexlify(msgs[0].encode("ascii"))
 
         # deallocate channel
@@ -83,7 +79,7 @@ class Initiator:
 
         return data
 
-class Receiver:
+class Receiver(Common):
     def __init__(self, appid, data, code, relay=RELAY):
         self.appid = appid
         self.data = data
@@ -99,26 +95,16 @@ class Receiver:
                            idA=self.appid+":Initiator",
                            idB=self.appid+":Receiver")
 
-    def url(self, suffix):
-        return "%s%d/%s/%s" % (self.relay, self.channel_id, self.side, suffix)
-
     def get_data(self):
         # post PAKE message
         msg = self.sp.start()
         post_data = {"message": hexlify(msg).decode("ascii")}
         r = requests.post(self.url("pake/post"), data=json.dumps(post_data))
         r.raise_for_status()
+        other_msgs = r.json()["messages"]
 
         # poll for PAKE response
-        while True:
-            r = requests.post(self.url("pake/poll"))
-            r.raise_for_status()
-            msgs = r.json()["messages"]
-            if msgs:
-                break
-            if time.time() > (self.started + self.timeout):
-                raise Timeout
-            time.sleep(self.wait)
+        msgs = self.poll(other_msgs, "pake/poll")
         pake_msg = unhexlify(msgs[0].encode("ascii"))
         self.key = self.sp.finish(pake_msg)
 
@@ -126,17 +112,10 @@ class Receiver:
         post_data = json.dumps({"message": hexlify(self.data).decode("ascii")})
         r = requests.post(self.url("data/post"), data=post_data)
         r.raise_for_status()
+        other_msgs = r.json()["messages"]
 
         # poll for data message
-        while True:
-            r = requests.post(self.url("data/poll"))
-            r.raise_for_status()
-            msgs = r.json()["messages"]
-            if msgs:
-                break
-            if time.time() > (self.started + self.timeout):
-                raise Timeout
-            time.sleep(self.wait)
+        msgs = self.poll(other_msgs, "data/poll")
         data = unhexlify(msgs[0].encode("ascii"))
 
         # deallocate channel