diff --git a/Lib/asyncore.py b/Lib/asyncore.py
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -535,6 +535,7 @@
         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 +549,15 @@
         self.out_buffer = self.out_buffer + data
         self.initiate_send()
 
+    def handle_close(self):
+        if not self.closing:
+            self.closing = True
+            # try to drain the output buffer
+            while self.writable() and self.initiate_send() > 0:
+                pass
+        self.close()
+
+
 # ---------------------------------------------------------------------------
 # used for debugging.
 # ---------------------------------------------------------------------------