diff --git a/Lib/asyncore.py b/Lib/asyncore.py
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -221,6 +221,7 @@
     connected = False
     accepting = False
     closing = False
+    pending_close_evt = False
     addr = None
     ignore_log_types = frozenset(['warning'])
 
@@ -380,6 +381,7 @@
             if not data:
                 # a closed connection is indicated by signaling
                 # a read condition, and having recv() return 0.
+                self.pending_close_evt = True
                 self.handle_close()
                 return b''
             else:
@@ -535,6 +537,7 @@
         num_sent = 0
         num_sent = dispatcher.send(self, self.out_buffer[:512])
         self.out_buffer = self.out_buffer[num_sent:]
+        return num_sent
 
     def handle_write(self):
         self.initiate_send()
@@ -548,6 +551,14 @@
         self.out_buffer = self.out_buffer + data
         self.initiate_send()
 
+    def handle_close(self):
+        if self.pending_close_evt:
+            self.pending_close_evt = False
+            # try to drain the output buffer
+            while self.writable() and self.initiate_send() > 0:
+                pass
+        self.close()
+
 # ---------------------------------------------------------------------------
 # used for debugging.
 # ---------------------------------------------------------------------------