diff --git a/libp2p/pubsub/floodsub.py b/libp2p/pubsub/floodsub.py
index 678e509..b7b7910 100644
--- a/libp2p/pubsub/floodsub.py
+++ b/libp2p/pubsub/floodsub.py
@@ -89,6 +89,8 @@ class FloodSub(IPubsubRouter):
         logger.debug("publishing message %s", pubsub_msg)
 
         for peer_id in peers_gen:
+            if peer_id not in self.pubsub.peers:
+                continue
             stream = self.pubsub.peers[peer_id]
             # FIXME: We should add a `WriteMsg` similar to write delimited messages.
             #   Ref: https://github.com/libp2p/go-libp2p-pubsub/blob/master/comm.go#L107
diff --git a/libp2p/pubsub/gossipsub.py b/libp2p/pubsub/gossipsub.py
index bddafa0..a64b9ca 100644
--- a/libp2p/pubsub/gossipsub.py
+++ b/libp2p/pubsub/gossipsub.py
@@ -193,6 +193,8 @@ class GossipSub(IPubsubRouter):
         logger.debug("publishing message %s", pubsub_msg)
 
         for peer_id in peers_gen:
+            if peer_id not in self.pubsub.peers:
+                continue
             stream = self.pubsub.peers[peer_id]
             # FIXME: We should add a `WriteMsg` similar to write delimited messages.
             #   Ref: https://github.com/libp2p/go-libp2p-pubsub/blob/master/comm.go#L107
@@ -604,6 +606,11 @@ class GossipSub(IPubsubRouter):
         rpc_msg: bytes = packet.SerializeToString()
 
         # 3) Get the stream to this peer
+        if sender_peer_id not in self.pubsub.peers:
+            logger.debug(
+                "Fail to responed to iwant request from %s: peer disconnected",
+                sender_peer_id,
+            )
         peer_stream = self.pubsub.peers[sender_peer_id]
 
         # 4) And write the packet to the stream
@@ -710,6 +717,8 @@ class GossipSub(IPubsubRouter):
         rpc_msg: bytes = packet.SerializeToString()
 
         # Get stream for peer from pubsub
+        if to_peer not in self.pubsub.peers:
+            logger.debug("Fail to emit control message to %s: peer disconnected", to_peer)
         peer_stream = self.pubsub.peers[to_peer]
 
         # Write rpc to stream