diff --git a/pkg/acl/treestorage/inmemory.go b/pkg/acl/treestorage/inmemory.go
index 3120d27a..8a2b7865 100644
--- a/pkg/acl/treestorage/inmemory.go
+++ b/pkg/acl/treestorage/inmemory.go
@@ -134,3 +134,34 @@ func (t *inMemoryTreeStorage) GetChange(ctx context.Context, changeId string) (*
 	}
 	return nil, fmt.Errorf("could not get change with id: %s", changeId)
 }
+
+type inMemoryTreeStorageProvider struct {
+	trees map[string]TreeStorage
+}
+
+func (i *inMemoryTreeStorageProvider) TreeStorage(treeId string) (TreeStorage, error) {
+	if tree, exists := i.trees[treeId]; exists {
+		return tree, nil
+	}
+	return nil, UnknownTreeId
+}
+
+func (i *inMemoryTreeStorageProvider) InsertTree(tree TreeStorage) error {
+	if tree == nil {
+		return fmt.Errorf("tree should not be nil")
+	}
+
+	id, err := tree.TreeID()
+	if err != nil {
+		return err
+	}
+
+	i.trees[id] = tree
+	return nil
+}
+
+func NewInMemoryTreeStorageProvider() Provider {
+	return &inMemoryTreeStorageProvider{
+		trees: make(map[string]TreeStorage),
+	}
+}
diff --git a/pkg/acl/treestorage/provider.go b/pkg/acl/treestorage/provider.go
index bf0c074c..c62096db 100644
--- a/pkg/acl/treestorage/provider.go
+++ b/pkg/acl/treestorage/provider.go
@@ -1,39 +1,10 @@
 package treestorage
 
-import "fmt"
+import "errors"
+
+var UnknownTreeId = errors.New("tree does not exist")
 
 type Provider interface {
 	TreeStorage(treeId string) (TreeStorage, error)
 	InsertTree(tree TreeStorage) error
 }
-
-type inMemoryTreeStorageProvider struct {
-	trees map[string]TreeStorage
-}
-
-func (i *inMemoryTreeStorageProvider) TreeStorage(treeId string) (TreeStorage, error) {
-	if tree, exists := i.trees[treeId]; exists {
-		return tree, nil
-	}
-	return nil, fmt.Errorf("tree with id %s doesn't exist", treeId)
-}
-
-func (i *inMemoryTreeStorageProvider) InsertTree(tree TreeStorage) error {
-	if tree == nil {
-		return fmt.Errorf("tree should not be nil")
-	}
-
-	id, err := tree.TreeID()
-	if err != nil {
-		return err
-	}
-
-	i.trees[id] = tree
-	return nil
-}
-
-func NewInMemoryTreeStorageProvider() Provider {
-	return &inMemoryTreeStorageProvider{
-		trees: make(map[string]TreeStorage),
-	}
-}
diff --git a/service/sync/requesthandler.go b/service/sync/requesthandler.go
index 65f2972d..b4d0758b 100644
--- a/service/sync/requesthandler.go
+++ b/service/sync/requesthandler.go
@@ -3,6 +3,7 @@ package sync
 import (
 	"context"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/acltree"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/treestorage"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/service/sync/syncpb"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/service/treecache"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/slice"
@@ -14,21 +15,12 @@ type requestHander struct {
 }
 
 func (r *requestHander) HandleHeadUpdate(ctx context.Context, senderId string, update *syncpb.SyncHeadUpdate) (err error) {
-	var fullRequest *syncpb.SyncFullRequest
-	var snapshotPath []string
-	var result acltree.AddResult
-	defer func() {
-		if err != nil || fullRequest != nil {
-			return
-		}
-		newUpdate := &syncpb.SyncHeadUpdate{
-			Heads:        result.Heads,
-			Changes:      result.Added,
-			SnapshotPath: snapshotPath,
-			TreeId:       update.TreeId,
-		}
-		err = r.client.NotifyHeadsChanged(newUpdate)
-	}()
+	var (
+		fullRequest  *syncpb.SyncFullRequest
+		snapshotPath []string
+		result       acltree.AddResult
+	)
+	
 	err = r.treeCache.Do(ctx, update.TreeId, func(tree acltree.ACLTree) error {
 		// TODO: check if we already have those changes
 		result, err = tree.AddRawChanges(ctx, update.Changes...)
@@ -45,16 +37,33 @@ func (r *requestHander) HandleHeadUpdate(ctx context.Context, senderId string, u
 		}
 		return nil
 	})
-	if err != nil {
-		return err
+	// if there are no such tree
+	if err == treestorage.UnknownTreeId {
+		fullRequest = &syncpb.SyncFullRequest{
+			TreeId: update.TreeId,
+		}
 	}
+	// if we have incompatible heads, or we haven't seen the tree at all
 	if fullRequest != nil {
 		return r.client.RequestFullSync(senderId, fullRequest)
 	}
+	// if error or nothing has changed
+	if err != nil || len(result.Added) == 0 {
+		return err
+	}
+	// otherwise sending heads update message
+	newUpdate := &syncpb.SyncHeadUpdate{
+		Heads:        result.Heads,
+		Changes:      result.Added,
+		SnapshotPath: snapshotPath,
+		TreeId:       update.TreeId,
+	}
+	err = r.client.NotifyHeadsChanged(newUpdate)
 	return
 }
 
 func (r *requestHander) HandleFullSync(ctx context.Context, senderId string, request *syncpb.SyncFullRequest) error {
+	// TODO: add case of new tree
 	return nil
 }