diff --git a/sjrpc/server/simple.py b/sjrpc/server/simple.py
index d46c703adcd06504cf29cbd1fcbf5bc428b7b98f..fb2f584a16f24281f5e62713a8ef370065faef63 100644
--- a/sjrpc/server/simple.py
+++ b/sjrpc/server/simple.py
@@ -45,8 +45,12 @@ class SimpleRpcServer(ConnectionManager):
         conn = self._clients.get(fd)
         self._poll.unregister(fd)
         if fd is not None:
-            del self._clients[fd]
-            conn.shutdown(callback=self._on_disconnect)
+            try:
+                del self._clients[fd]
+            except KeyError:
+                pass
+            if conn is not None:
+                conn.shutdown(callback=self._on_disconnect)
 
     def all_connections(self):
         return set(self._clients.values())