diff --git a/codex/blockexchange/engine/discovery.nim b/codex/blockexchange/engine/discovery.nim
index 16ef560b..78630f13 100644
--- a/codex/blockexchange/engine/discovery.nim
+++ b/codex/blockexchange/engine/discovery.nim
@@ -131,6 +131,7 @@ proc queueFindBlocksReq*(b: DiscoveryEngine, cids: seq[Cid]) {.inline.} =
   for cid in cids:
     if cid notin b.discoveryQueue:
       try:
+        trace "Discovery Started", cid
         b.discoveryQueue.putNoWait(cid)
       except CatchableError as exc:
         warn "Exception queueing discovery request", exc = exc.msg
diff --git a/codex/blockexchange/engine/engine.nim b/codex/blockexchange/engine/engine.nim
index 0b02ce61..ef4eb013 100644
--- a/codex/blockexchange/engine/engine.nim
+++ b/codex/blockexchange/engine/engine.nim
@@ -223,7 +223,7 @@ proc blockPresenceHandler*(
   if peerCtx.isNil:
     return
 
-  trace "Handling blockPresences", addrs = blocks.mapIt(it.address)
+  trace "Handling blockPresences", addrs = blocks.mapIt(it.address), anyCancel = blocks.anyIt(it.isCancel)
   for blk in blocks:
     if presence =? Presence.init(blk):
       peerCtx.setPresence(presence)
@@ -432,7 +432,8 @@ proc wantListHandler*(
               BlockPresence(
               address: e.address,
               `type`: BlockPresenceType.DontHave,
-              price: price))
+              price: price,
+              isCancel: e.cancel))
         elif have: # and not e.cancel: # Uncomment this for slow mode.
           # Important todo: This presence can be added in response to a cancel message.
           # This is ignored by the receiving peer. But not doing so degrades performance.
@@ -442,7 +443,8 @@ proc wantListHandler*(
             BlockPresence(
             address: e.address,
             `type`: BlockPresenceType.Have,
-            price: price))
+            price: price,
+            isCancel: e.cancel))
 
       elif e.wantType == WantType.WantBlock and not e.cancel:
         # cancels are always of type wantHave, but just in case
@@ -458,7 +460,7 @@ proc wantListHandler*(
         peerCtx.peerWants[idx] = e # update entry
 
   if presence.len > 0:
-    trace "Sending presence", addrs = presence.mapIt(it.address)
+    trace "Sending presence", addrs = presence.mapIt(it.address), anyCancel = presence.anyIt(it.isCancel)
     await b.network.request.sendPresence(peer, presence)
 
   if schedulePeer:
diff --git a/codex/blockexchange/protobuf/message.nim b/codex/blockexchange/protobuf/message.nim
index 61488b40..19080e80 100644
--- a/codex/blockexchange/protobuf/message.nim
+++ b/codex/blockexchange/protobuf/message.nim
@@ -48,6 +48,7 @@ type
     address*: BlockAddress
     `type`*: BlockPresenceType
     price*: seq[byte]       # Amount of assets to pay for the block (UInt256)
+    isCancel*: bool
 
   AccountMessage* = object
     address*: seq[byte]     # Ethereum address to which payments should be made
@@ -112,6 +113,7 @@ proc write*(pb: var ProtoBuffer, field: int, value: BlockPresence) =
   ipb.write(1, value.address)
   ipb.write(2, value.`type`.uint)
   ipb.write(3, value.price)
+  ipb.write(4, value.isCancel.uint)
   ipb.finish()
   pb.write(field, ipb)
 
@@ -237,6 +239,8 @@ proc decode*(_: type BlockPresence, pb: ProtoBuffer): ProtoResult[BlockPresence]
   if ? pb.getField(2, field):
     value.`type` = BlockPresenceType(field)
   discard ? pb.getField(3, value.price)
+  if ? pb.getField(4, field):
+    value.isCancel = bool(field)
   ok(value)
 
 proc decode*(_: type AccountMessage, pb: ProtoBuffer): ProtoResult[AccountMessage] =
diff --git a/docker/build.bat b/docker/build.bat
index c25eabab..87dca68d 100644
--- a/docker/build.bat
+++ b/docker/build.bat
@@ -1,2 +1,2 @@
-docker build --build-arg MAKE_PARALLEL=4 --build-arg NIMFLAGS="-d:disableMarchNative -d:codex_enable_api_debug_peers=true -d:codex_enable_proof_failures=true -d:codex_use_hardhat=false -d:codex_enable_log_counter=true -d:verify_circuit=true" --build-arg NAT_IP_AUTO=true -t thatbenbierens/nim-codex:blkex-cancelpresence-15 -f codex.Dockerfile ..
-docker push thatbenbierens/nim-codex:blkex-cancelpresence-15
+docker build --build-arg MAKE_PARALLEL=4 --build-arg NIMFLAGS="-d:disableMarchNative -d:codex_enable_api_debug_peers=true -d:codex_enable_proof_failures=true -d:codex_use_hardhat=false -d:codex_enable_log_counter=true -d:verify_circuit=true" --build-arg NAT_IP_AUTO=true -t thatbenbierens/nim-codex:blkex-cancelpresence-18-s -f codex.Dockerfile ..
+docker push thatbenbierens/nim-codex:blkex-cancelpresence-18-s