diff --git a/tl/generate/scheme/ton_api.tl b/tl/generate/scheme/ton_api.tl
index 3d14ac65..57ed9ddc 100644
--- a/tl/generate/scheme/ton_api.tl
+++ b/tl/generate/scheme/ton_api.tl
@@ -307,6 +307,8 @@ validatorSession.candidate src:int256 round:int root_hash:int256 data:bytes coll
 
 validatorSession.config catchain_idle_timeout:double catchain_max_deps:int round_candidates:int next_candidate_delay:double round_attempt_duration:int
         max_round_attempts:int max_block_size:int max_collated_data_size:int = validatorSession.Config;
+validatorSession.configVersioned catchain_idle_timeout:double catchain_max_deps:int round_candidates:int next_candidate_delay:double round_attempt_duration:int
+        max_round_attempts:int max_block_size:int max_collated_data_size:int version:int = validatorSession.Config;
 validatorSession.configNew catchain_idle_timeout:double catchain_max_deps:int round_candidates:int next_candidate_delay:double round_attempt_duration:int
         max_round_attempts:int max_block_size:int max_collated_data_size:int new_catchain_ids:Bool = validatorSession.Config;
 
diff --git a/tl/generate/scheme/ton_api.tlo b/tl/generate/scheme/ton_api.tlo
index 65ec36c5..823219b5 100644
Binary files a/tl/generate/scheme/ton_api.tlo and b/tl/generate/scheme/ton_api.tlo differ
diff --git a/validator-session/validator-session-types.h b/validator-session/validator-session-types.h
index 6e58813b..812c20b8 100644
--- a/validator-session/validator-session-types.h
+++ b/validator-session/validator-session-types.h
@@ -53,6 +53,8 @@ struct ValidatorSessionOptions {
 
   bool new_catchain_ids = false;
 
+  td::uint32 proto_version = 0;
+
   td::Bits256 get_hash() const;
 };
 
diff --git a/validator-session/validator-session.cpp b/validator-session/validator-session.cpp
index e59b27b6..088d2957 100644
--- a/validator-session/validator-session.cpp
+++ b/validator-session/validator-session.cpp
@@ -881,19 +881,26 @@ td::actor::ActorOwn<ValidatorSession> ValidatorSession::create(
 }
 
 td::Bits256 ValidatorSessionOptions::get_hash() const {
-  if (!new_catchain_ids) {
-    return create_hash_tl_object<ton_api::validatorSession_config>(
-        catchain_idle_timeout, catchain_max_deps, round_candidates, next_candidate_delay, round_attempt_duration,
-        max_round_attempts, max_block_size, max_collated_data_size);
+  if(!proto_version) {
+    if (!new_catchain_ids) {
+        return create_hash_tl_object<ton_api::validatorSession_config>(
+            catchain_idle_timeout, catchain_max_deps, round_candidates, next_candidate_delay, round_attempt_duration,
+            max_round_attempts, max_block_size, max_collated_data_size);
+    } else {
+        return create_hash_tl_object<ton_api::validatorSession_configNew>(
+            catchain_idle_timeout, catchain_max_deps, round_candidates, next_candidate_delay, round_attempt_duration,
+            max_round_attempts, max_block_size, max_collated_data_size, new_catchain_ids);
+    }
   } else {
-    return create_hash_tl_object<ton_api::validatorSession_configNew>(
-        catchain_idle_timeout, catchain_max_deps, round_candidates, next_candidate_delay, round_attempt_duration,
-        max_round_attempts, max_block_size, max_collated_data_size, new_catchain_ids);
-  }
+        return create_hash_tl_object<ton_api::validatorSession_configVersioned>(
+            catchain_idle_timeout, catchain_max_deps, round_candidates, next_candidate_delay, round_attempt_duration,
+            max_round_attempts, max_block_size, max_collated_data_size, proto_version);
+    }
+
 }
 
 ValidatorSessionOptions::ValidatorSessionOptions(const ValidatorSessionConfig &conf) {
-  CHECK(!conf.proto_version);
+  proto_version = conf.proto_version;
   catchain_idle_timeout = conf.catchain_idle_timeout;
   catchain_max_deps = conf.catchain_max_deps;
   max_block_size = conf.max_block_size;
diff --git a/validator/manager.cpp b/validator/manager.cpp
index 2fcd182a..2c43a5dd 100644
--- a/validator/manager.cpp
+++ b/validator/manager.cpp
@@ -1692,6 +1692,12 @@ void ValidatorManagerImpl::update_shards() {
   auto exp_vec = last_masterchain_state_->get_shards();
   auto config = last_masterchain_state_->get_consensus_config();
   validatorsession::ValidatorSessionOptions opts{config};
+  uint threshold = 9344000;
+  bool force_group_id_upgrade = last_masterchain_seqno_ == threshold;
+  auto legacy_opts_hash = opts.get_hash();
+  if(last_masterchain_seqno_ >= threshold) { //TODO move to get_consensus_config()
+      opts.proto_version = 1;
+  }
   auto opts_hash = opts.get_hash();
 
   std::map<ShardIdFull, std::vector<BlockIdExt>> new_shards;
@@ -1766,6 +1772,45 @@ void ValidatorManagerImpl::update_shards() {
 
   BlockSeqno key_seqno = last_key_block_handle_->id().seqno();
 
+  if (force_group_id_upgrade) {
+    for (auto &desc : new_shards) {
+      auto shard = desc.first;
+      auto prev = desc.second;
+      for (auto &p : prev) {
+        CHECK(p.is_valid());
+      }
+      auto val_set = last_masterchain_state_->get_validator_set(shard);
+      auto validator_id = get_validator(shard, val_set);
+
+      if (!validator_id.is_zero()) {
+        auto legacy_val_group_id = get_validator_set_id(shard, val_set, legacy_opts_hash, key_seqno, opts);
+        auto val_group_id = get_validator_set_id(shard, val_set, opts_hash, key_seqno, opts);
+
+
+        auto it = validator_groups_.find(legacy_val_group_id);
+        if (it != validator_groups_.end()) {
+          new_validator_groups_.emplace(val_group_id, std::move(it->second));
+        } else {
+          auto it2 = next_validator_groups_.find(legacy_val_group_id);
+          if (it2 != next_validator_groups_.end()) {
+            if (!it2->second.empty()) {
+              td::actor::send_closure(it2->second, &ValidatorGroup::start, prev, last_masterchain_block_id_,
+                                      last_masterchain_state_->get_unix_time());
+            }
+            new_validator_groups_.emplace(val_group_id, std::move(it2->second));
+          } else {
+            auto G = create_validator_group(val_group_id, shard, val_set, opts, started_);
+            if (!G.empty()) {
+              td::actor::send_closure(G, &ValidatorGroup::start, prev, last_masterchain_block_id_,
+                                      last_masterchain_state_->get_unix_time());
+            }
+            new_validator_groups_.emplace(val_group_id, std::move(G));
+          }
+        }
+      }
+    }
+  }
+
   if (allow_validate_) {
     for (auto &desc : new_shards) {
       auto shard = desc.first;