diff --git a/lib/interface.py b/lib/interface.py
index 68658f0f5..d530a5e4d 100644
--- a/lib/interface.py
+++ b/lib/interface.py
@@ -257,10 +257,15 @@ class Interface(util.PrintError):
         self.request_time = time.time()
         self.unsent_requests.append(args)
 
+    def num_requests(self):
+        '''Keep unanswered requests below 100'''
+        n = 100 - len(self.unanswered_requests)
+        return min(n, len(self.unsent_requests))
+
     def send_requests(self):
         '''Sends queued requests.  Returns False on failure.'''
         make_dict = lambda (m, p, i): {'method': m, 'params': p, 'id': i}
-        n = 100 - len(self.unanswered_requests)
+        n = self.num_requests()
         wire_requests = self.unsent_requests[0:n]
         try:
             self.pipe.send_all(map(make_dict, wire_requests))
diff --git a/lib/network.py b/lib/network.py
index 322d81a79..bf4421774 100644
--- a/lib/network.py
+++ b/lib/network.py
@@ -788,7 +788,7 @@ class Network(util.DaemonThread):
             time.sleep(0.1)
             return
         rin = [i for i in self.interfaces.values()]
-        win = [i for i in self.interfaces.values() if i.unsent_requests]
+        win = [i for i in self.interfaces.values() if i.num_requests()]
         try:
             rout, wout, xout = select.select(rin, win, [], 0.1)
         except socket.error as (code, msg):