diff --git a/validator/full-node-shard.cpp b/validator/full-node-shard.cpp
index 53c086e3a..8e42716bf 100644
--- a/validator/full-node-shard.cpp
+++ b/validator/full-node-shard.cpp
@@ -109,7 +109,8 @@ void FullNodeShardImpl::check_broadcast(PublicKeyHash src, td::BufferSlice broad
   }
 
   auto q = B.move_as_ok();
-  if (!processed_ext_msg_broadcasts_.insert(td::sha256_bits256(q->message_->data_)).second) {
+  auto hash = td::sha256_bits256(q->message_->data_);
+  if (!processed_ext_msg_broadcasts_.insert(hash).second) {
     return promise.set_error(td::Status::Error("duplicate external message broadcast"));
   }
   if (config_.ext_messages_broadcast_disabled_) {
@@ -120,6 +121,11 @@ void FullNodeShardImpl::check_broadcast(PublicKeyHash src, td::BufferSlice broad
       }
     };
   }
+  if (my_ext_msg_broadcasts_.count(hash)) {
+    // Don't re-check messages that were sent by us
+    promise.set_result(td::Unit());
+    return;
+  }
   td::actor::send_closure(validator_manager_, &ValidatorManagerInterface::check_external_message,
                           std::move(q->message_->data_),
                           promise.wrap([](td::Ref<ExtMessage>) { return td::Unit(); }));
@@ -706,9 +712,11 @@ void FullNodeShardImpl::send_external_message(td::BufferSlice data) {
                             });
     return;
   }
-  if (!processed_ext_msg_broadcasts_.insert(td::sha256_bits256(data)).second) {
+  td::Bits256 hash = td::sha256_bits256(data);
+  if (processed_ext_msg_broadcasts_.count(hash)) {
     return;
   }
+  my_ext_msg_broadcasts_.insert(hash);
   auto B = create_serialize_tl_object<ton_api::tonNode_externalMessageBroadcast>(
       create_tl_object<ton_api::tonNode_externalMessage>(std::move(data)));
   if (B.size() <= overlay::Overlays::max_simple_broadcast_size()) {
@@ -860,6 +868,7 @@ void FullNodeShardImpl::alarm() {
   }
   if (cleanup_processed_ext_msg_at_ && cleanup_processed_ext_msg_at_.is_in_past()) {
     processed_ext_msg_broadcasts_.clear();
+    my_ext_msg_broadcasts_.clear();
     cleanup_processed_ext_msg_at_ = td::Timestamp::in(60.0);
   }
   alarm_timestamp().relax(sync_completed_at_);
diff --git a/validator/full-node-shard.hpp b/validator/full-node-shard.hpp
index faf495985..0525474e6 100644
--- a/validator/full-node-shard.hpp
+++ b/validator/full-node-shard.hpp
@@ -252,6 +252,7 @@ class FullNodeShardImpl : public FullNodeShard {
 
   FullNodeConfig config_;
 
+  std::set<td::Bits256> my_ext_msg_broadcasts_;
   std::set<td::Bits256> processed_ext_msg_broadcasts_;
   td::Timestamp cleanup_processed_ext_msg_at_;
 };