diff --git a/libp2p/protocols/pubsub/gossipsub.nim b/libp2p/protocols/pubsub/gossipsub.nim
index e83e5d7a6..e9fb57ffb 100644
--- a/libp2p/protocols/pubsub/gossipsub.nim
+++ b/libp2p/protocols/pubsub/gossipsub.nim
@@ -223,7 +223,8 @@ method init*(g: GossipSub) =
       trace "GossipSub handler leaks an error", exc = exc.msg, conn
 
   g.handler = handler
-  g.codecs &= GossipSubCodec
+  g.codecs &= GossipSubCodec_12
+  g.codecs &= GossipSubCodec_11
   g.codecs &= GossipSubCodec_10
 
 method onNewPeer*(g: GossipSub, peer: PubSubPeer) =
@@ -408,10 +409,10 @@ proc validateAndRelay(
       # descored) and that the savings from honest peers are greater than the
       # cost a dishonest peer can incur in short time (since the IDONTWANT is
       # small).
-      var toSendPeers = HashSet[PubSubPeer]()
-      addToSendPeers(toSendPeers)
+      var peersToSendIDontWant = HashSet[PubSubPeer]()
+      addToSendPeers(peersToSendIDontWant)
       g.broadcast(
-        toSendPeers,
+        peersToSendIDontWant,
         RPCMsg(
           control:
             some(ControlMessage(idontwant: @[ControlIWant(messageIDs: @[msgId])]))
@@ -456,18 +457,17 @@ proc validateAndRelay(
     # Don't send it to peers that sent it during validation
     toSendPeers.excl(seenPeers)
 
-    var peersWhoSentIdontwant = HashSet[PubSubPeer]()
-    for peer in toSendPeers:
-      for heDontWant in peer.heDontWants:
-        if saltedId in heDontWant:
-          peersWhoSentIdontwant.incl(peer)
+    proc isMsgInIdontWant(it: PubSubPeer): bool =
+      for iDontWant in it.iDontWants:
+        if saltedId in iDontWant:
           libp2p_gossipsub_idontwant_saved_messages.inc
           libp2p_gossipsub_saved_bytes.inc(
             msg.data.len.int64, labelValues = ["idontwant"]
           )
-          break
-    toSendPeers.excl(peersWhoSentIdontwant)
-      # avoids len(s) == length` the length of the HashSet changed while iterating over it [AssertionDefect]
+          return true
+      return false
+
+    toSendPeers.exclIfIt(isMsgInIdontWant(it))
 
     # In theory, if topics are the same in all messages, we could batch - we'd
     # also have to be careful to only include validated messages
diff --git a/libp2p/protocols/pubsub/gossipsub/behavior.nim b/libp2p/protocols/pubsub/gossipsub/behavior.nim
index 889b73ac3..bbcfa0c07 100644
--- a/libp2p/protocols/pubsub/gossipsub/behavior.nim
+++ b/libp2p/protocols/pubsub/gossipsub/behavior.nim
@@ -306,9 +306,9 @@ proc handleIHave*(
 proc handleIDontWant*(g: GossipSub, peer: PubSubPeer, iDontWants: seq[ControlIWant]) =
   for dontWant in iDontWants:
     for messageId in dontWant.messageIDs:
-      if peer.heDontWants[^1].len > 1000:
+      if peer.iDontWants[^1].len > 1000:
         break
-      peer.heDontWants[^1].incl(g.salt(messageId))
+      peer.iDontWants[^1].incl(g.salt(messageId))
 
 proc handleIWant*(
     g: GossipSub, peer: PubSubPeer, iwants: seq[ControlIWant]
@@ -705,9 +705,9 @@ proc onHeartbeat(g: GossipSub) =
       peer.sentIHaves.addFirst(default(HashSet[MessageId]))
       if peer.sentIHaves.len > g.parameters.historyLength:
         discard peer.sentIHaves.popLast()
-      peer.heDontWants.addFirst(default(HashSet[SaltedId]))
-      if peer.heDontWants.len > g.parameters.historyLength:
-        discard peer.heDontWants.popLast()
+      peer.iDontWants.addFirst(default(HashSet[SaltedId]))
+      if peer.iDontWants.len > g.parameters.historyLength:
+        discard peer.iDontWants.popLast()
       peer.iHaveBudget = IHavePeerBudget
       peer.pingBudget = PingsPeerBudget
 
diff --git a/libp2p/protocols/pubsub/gossipsub/types.nim b/libp2p/protocols/pubsub/gossipsub/types.nim
index 3fb98749a..d50e09824 100644
--- a/libp2p/protocols/pubsub/gossipsub/types.nim
+++ b/libp2p/protocols/pubsub/gossipsub/types.nim
@@ -18,7 +18,8 @@ import "../../.."/[peerid, multiaddress, utility]
 export options, tables, sets
 
 const
-  GossipSubCodec* = "/meshsub/1.1.0"
+  GossipSubCodec_12* = "/meshsub/1.2.0"
+  GossipSubCodec_11* = "/meshsub/1.1.0"
   GossipSubCodec_10* = "/meshsub/1.0.0"
 
 # overlay parameters
diff --git a/libp2p/protocols/pubsub/pubsubpeer.nim b/libp2p/protocols/pubsub/pubsubpeer.nim
index 2e40a6dc0..9dd00f66a 100644
--- a/libp2p/protocols/pubsub/pubsubpeer.nim
+++ b/libp2p/protocols/pubsub/pubsubpeer.nim
@@ -103,7 +103,7 @@ type
 
     score*: float64
     sentIHaves*: Deque[HashSet[MessageId]]
-    heDontWants*: Deque[HashSet[SaltedId]]
+    iDontWants*: Deque[HashSet[SaltedId]]
       ## IDONTWANT contains unvalidated message id:s which may be long and/or
       ## expensive to look up, so we apply the same salting to them as during
       ## unvalidated message processing
@@ -545,5 +545,5 @@ proc new*(
     maxNumElementsInNonPriorityQueue: maxNumElementsInNonPriorityQueue,
   )
   result.sentIHaves.addFirst(default(HashSet[MessageId]))
-  result.heDontWants.addFirst(default(HashSet[SaltedId]))
+  result.iDontWants.addFirst(default(HashSet[SaltedId]))
   result.startSendNonPriorityTask()
diff --git a/libp2p/utility.nim b/libp2p/utility.nim
index 8b0870a45..542eff026 100644
--- a/libp2p/utility.nim
+++ b/libp2p/utility.nim
@@ -9,7 +9,7 @@
 
 {.push raises: [].}
 
-import std/options, std/macros
+import std/[sets, options, macros]
 import stew/[byteutils, results]
 
 export results
@@ -140,3 +140,11 @@ template toOpt*[T, E](self: Result[T, E]): Opt[T] =
       Opt.some(temp.unsafeGet())
   else:
     Opt.none(type(T))
+
+template exclIfIt*[T](set: var HashSet[T], condition: untyped) =
+  if set.len != 0:
+    var toExcl = HashSet[T]()
+    for it {.inject.} in set:
+      if condition:
+        toExcl.incl(it)
+    set.excl(toExcl)
diff --git a/tests/pubsub/testgossipsub.nim b/tests/pubsub/testgossipsub.nim
index ac4eb9595..b6cc5828f 100644
--- a/tests/pubsub/testgossipsub.nim
+++ b/tests/pubsub/testgossipsub.nim
@@ -854,16 +854,16 @@ suite "GossipSub":
       isHighPriority = true,
     )
     checkUntilTimeout:
-      gossip2.mesh.getOrDefault("foobar").anyIt(it.heDontWants[^1].len == 1)
+      gossip2.mesh.getOrDefault("foobar").anyIt(it.iDontWants[^1].len == 1)
 
     tryPublish await nodes[0].publish("foobar", newSeq[byte](10000)), 1
 
     await bFinished
 
     checkUntilTimeout:
-      toSeq(gossip3.mesh.getOrDefault("foobar")).anyIt(it.heDontWants[^1].len == 1)
+      toSeq(gossip3.mesh.getOrDefault("foobar")).anyIt(it.iDontWants[^1].len == 1)
     check:
-      toSeq(gossip1.mesh.getOrDefault("foobar")).anyIt(it.heDontWants[^1].len == 0)
+      toSeq(gossip1.mesh.getOrDefault("foobar")).anyIt(it.iDontWants[^1].len == 0)
 
     await allFuturesThrowing(
       nodes[0].switch.stop(), nodes[1].switch.stop(), nodes[2].switch.stop()
diff --git a/tests/pubsub/utils.nim b/tests/pubsub/utils.nim
index 0d009deb0..abe7aa2ed 100644
--- a/tests/pubsub/utils.nim
+++ b/tests/pubsub/utils.nim
@@ -28,9 +28,9 @@ type TestGossipSub* = ref object of GossipSub
 
 proc getPubSubPeer*(p: TestGossipSub, peerId: PeerId): PubSubPeer =
   proc getConn(): Future[Connection] =
-    p.switch.dial(peerId, GossipSubCodec)
+    p.switch.dial(peerId, GossipSubCodec_12)
 
-  let pubSubPeer = PubSubPeer.new(peerId, getConn, nil, GossipSubCodec, 1024 * 1024)
+  let pubSubPeer = PubSubPeer.new(peerId, getConn, nil, GossipSubCodec_12, 1024 * 1024)
   debug "created new pubsub peer", peerId
 
   p.peers[peerId] = pubSubPeer