diff --git a/server/db/mysql/group_schema_test.go b/server/db/mysql/group_schema_test.go
index 09bad53..9573112 100644
--- a/server/db/mysql/group_schema_test.go
+++ b/server/db/mysql/group_schema_test.go
@@ -117,14 +117,14 @@ func TestTenantPartitionTableNames(t *testing.T) {
 
 func TestTenantShardSQL(t *testing.T) {
 	query := tenantShardSQL(7, "SELECT * FROM im_topics t JOIN im_group_members gm ON gm.topic=t.name JOIN im_subscriptions s ON s.topic=gm.topic; INSERT INTO im_system_notifications(event_id) VALUES(?)")
-	for _, expected := range []string{"im_topics", "im_group_members", "im_subscriptions", "im_system_notifications"} {
+	for _, expected := range []string{"im_007_topics", "im_007_group_members", "im_007_subscriptions", "im_007_system_notifications"} {
 		if !strings.Contains(query, expected) {
-			t.Fatalf("shared tenant query is missing %q: %s", expected, query)
+			t.Fatalf("tenant shard query is missing %q: %s", expected, query)
 		}
 	}
-	for _, legacy := range []string{"im_007_topics", "im_007_group_members", "im_007_subscriptions", "im_007_system_notifications"} {
-		if strings.Contains(query, legacy) {
-			t.Fatalf("shared tenant query should not reference %q: %s", legacy, query)
+	for _, shared := range []string{" im_topics ", " im_group_members ", " im_subscriptions ", " im_system_notifications"} {
+		if strings.Contains(query, shared) {
+			t.Fatalf("tenant shard query should not reference shared table %q: %s", shared, query)
 		}
 	}
 }
diff --git a/server/db/mysql/tenant_groups.go b/server/db/mysql/tenant_groups.go
index 6ec4c3e..05aad15 100644
--- a/server/db/mysql/tenant_groups.go
+++ b/server/db/mysql/tenant_groups.go
@@ -17,7 +17,7 @@ import (
 )
 
 const (
-	groupSettingsSelectColumns = `topic,owner_user_id,name,avatar_file_id,description,group_status,join_approval,mute_all,
+	groupSettingsSelectColumns = `tenant_id,topic,owner_user_id,name,avatar_file_id,description,group_status,join_approval,mute_all,
 		member_upload_files,member_private_chat,member_invite,max_member_count,max_admin_count,member_count,version,
 		created_by,dissolved_by,dissolved_at,created_at,updated_at`
 	groupAnnouncementSelectColumnsBase = `id,announcement_id,topic,author_user_id,content,status,version,published_at,idempotency_key,created_at,updated_at,
@@ -66,10 +66,10 @@ func (a *adapter) TenantGroupSettingsCreate(id t.TenantID, settings *t.GroupSett
 		return nil, err
 	}
 	_, err = a.db.ExecContext(ctx, `INSERT INTO im_group_settings
-		(id,topic,owner_user_id,name,avatar_file_id,description,group_status,join_approval,mute_all,member_upload_files,member_private_chat,member_invite,max_member_count,max_admin_count,member_count,version,created_by,created_at,updated_at)
-		VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
+		(id,tenant_id,topic,owner_user_id,name,avatar_file_id,description,group_status,join_approval,mute_all,member_upload_files,member_private_chat,member_invite,max_member_count,max_admin_count,member_count,version,created_by,created_at,updated_at)
+		VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
 		ON DUPLICATE KEY UPDATE name=VALUES(name),avatar_file_id=VALUES(avatar_file_id),description=VALUES(description),updated_at=VALUES(updated_at)`,
-		settingsID, settings.Topic, decodeUID(settings.OwnerUserID), settings.Name, settings.AvatarFileID, settings.Description, settings.GroupStatus,
+		settingsID, id, settings.Topic, decodeUID(settings.OwnerUserID), settings.Name, settings.AvatarFileID, settings.Description, settings.GroupStatus,
 		settings.JoinApproval, settings.MuteAll, settings.MemberUploadFiles, settings.MemberPrivateChat, settings.MemberInvite,
 		settings.MaxMemberCount, settings.MaxAdminCount, settings.MemberCount, settings.Version, decodeUID(settings.CreatedBy), settings.CreatedAt, settings.UpdatedAt)
 	if err != nil {
@@ -91,7 +91,7 @@ func (a *adapter) TenantGroupSettingsGet(id t.TenantID, topic string) (*t.GroupS
 	if cancel != nil {
 		defer cancel()
 	}
-	return a.groupSettingsByTopic(ctx, topic)
+	return a.groupSettingsByTopic(ctx, id, topic)
 }
 
 func (a *adapter) TenantGroupSettingsUpdate(id t.TenantID, topic string, patch t.GroupSettingsPatch) (*t.GroupSettings, error) {
@@ -154,8 +154,8 @@ func (a *adapter) TenantGroupSettingsUpdate(id t.TenantID, topic string, patch t
 		args = append(args, patch.MemberCountDelta)
 	}
 	set = append(set, "version=version+1")
-	args = append(args, topic)
-	where := "topic=?"
+	args = append(args, id, topic)
+	where := "tenant_id=? AND topic=?"
 	if patch.Version > 0 {
 		where += " AND version=?"
 		args = append(args, patch.Version)
@@ -187,7 +187,7 @@ func (a *adapter) TenantGroupSettingsUpdate(id t.TenantID, topic string, patch t
 	if err = tx.Commit(); err != nil {
 		return nil, err
 	}
-	return a.groupSettingsByTopic(ctx, topic)
+	return a.groupSettingsByTopic(ctx, id, topic)
 }
 
 func (a *adapter) TenantGroupDissolve(id t.TenantID, topic string, actor t.Uid, reason string, now time.Time) (*t.GroupSettings, error) {
@@ -213,7 +213,7 @@ func (a *adapter) TenantGroupDissolve(id t.TenantID, topic string, actor t.Uid,
 	defer tx.Rollback()
 	res, err := tx.ExecContext(ctx, `UPDATE im_group_settings
 		SET group_status='dissolved',dissolved_by=?,dissolved_at=?,member_count=0,version=version+1,updated_at=?
-		WHERE topic=? AND group_status<>'dissolved'`, decodeUID(actor), now, now, strings.TrimSpace(topic))
+		WHERE tenant_id=? AND topic=? AND group_status<>'dissolved'`, decodeUID(actor), now, now, id, strings.TrimSpace(topic))
 	if err != nil {
 		return nil, err
 	}
@@ -238,7 +238,7 @@ func (a *adapter) TenantGroupDissolve(id t.TenantID, topic string, actor t.Uid,
 	if err = tx.Commit(); err != nil {
 		return nil, err
 	}
-	return a.groupSettingsByTopic(ctx, topic)
+	return a.groupSettingsByTopic(ctx, id, topic)
 }
 
 func (a *adapter) TenantGroupMemberUpsert(id t.TenantID, member *t.GroupMember) (*t.GroupMember, error) {
@@ -1245,7 +1245,7 @@ func (a *adapter) TenantGroupCreate(id t.TenantID, topic *t.Topic, owner t.Uid,
 		return err
 	}
 	settings.MemberCount = 1
-	if err = insertGroupSettingsTx(tx, settings); err != nil {
+	if err = insertGroupSettingsTx(tx, id, settings); err != nil {
 		return err
 	}
 	ownerMember := &t.GroupMember{Topic: topic.Id, UserID: owner, Role: t.GroupMemberRoleOwner,
@@ -1458,8 +1458,8 @@ func (a *adapter) TenantGroupOwnerTransfer(id t.TenantID, topic string, previous
 	if _, err = tx.ExecContext(ctx, tenantShardSQL(id, "UPDATE im_topics SET owner=?,updatedat=? WHERE tenant_id=? AND name=?"), decodeUID(newOwner), now, id, topic); err != nil {
 		return err
 	}
-	args := []any{decodeUID(newOwner), now, topic}
-	query := "UPDATE im_group_settings SET owner_user_id=?,version=version+1,updated_at=? WHERE topic=?"
+	args := []any{decodeUID(newOwner), now, id, topic}
+	query := "UPDATE im_group_settings SET owner_user_id=?,version=version+1,updated_at=? WHERE tenant_id=? AND topic=?"
 	if version > 0 {
 		query += " AND version=?"
 		args = append(args, version)
@@ -1489,23 +1489,23 @@ func (a *adapter) TenantGroupCanPost(id t.TenantID, topic string, uid t.Uid, adm
 	}
 	var muteAll, memberMuted bool
 	err := a.db.QueryRowContext(ctx, `SELECT
-		COALESCE((SELECT mute_all FROM im_group_settings WHERE topic=? AND group_status=? LIMIT 1),0),
+		COALESCE((SELECT mute_all FROM im_group_settings WHERE tenant_id=? AND topic=? AND group_status=? LIMIT 1),0),
 		EXISTS(SELECT 1 FROM im_group_mutes WHERE topic=? AND user_id=? AND status=? AND (expires_at IS NULL OR expires_at>?))`,
-		topic, t.GroupStatusActive, topic, decodeUID(uid), t.GroupMuteStatusActive, now).Scan(&muteAll, &memberMuted)
+		id, topic, t.GroupStatusActive, topic, decodeUID(uid), t.GroupMuteStatusActive, now).Scan(&muteAll, &memberMuted)
 	if err != nil {
 		return false, err
 	}
 	return !muteAll && !memberMuted, nil
 }
 
-func insertGroupSettingsTx(tx *sqlx.Tx, settings *t.GroupSettings) error {
+func insertGroupSettingsTx(tx *sqlx.Tx, tenantID t.TenantID, settings *t.GroupSettings) error {
 	settingsID, err := nextSnowflakeID()
 	if err != nil {
 		return err
 	}
 	_, err = tx.Exec(`INSERT INTO im_group_settings
-		(id,topic,owner_user_id,name,avatar_file_id,description,group_status,join_approval,mute_all,member_upload_files,member_private_chat,member_invite,max_member_count,max_admin_count,member_count,version,created_by,created_at,updated_at)
-		VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`, settingsID, settings.Topic, decodeUID(settings.OwnerUserID), settings.Name,
+		(id,tenant_id,topic,owner_user_id,name,avatar_file_id,description,group_status,join_approval,mute_all,member_upload_files,member_private_chat,member_invite,max_member_count,max_admin_count,member_count,version,created_by,created_at,updated_at)
+		VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`, settingsID, tenantID, settings.Topic, decodeUID(settings.OwnerUserID), settings.Name,
 		settings.AvatarFileID, settings.Description, settings.GroupStatus, settings.JoinApproval, settings.MuteAll,
 		settings.MemberUploadFiles, settings.MemberPrivateChat, settings.MemberInvite, settings.MaxMemberCount,
 		settings.MaxAdminCount, settings.MemberCount, settings.Version, decodeUID(settings.CreatedBy), settings.CreatedAt, settings.UpdatedAt)
@@ -1569,9 +1569,9 @@ func (a *adapter) routeGroupTenant(id t.TenantID) (*adapter, error) {
 	return a, validTenant(id)
 }
 
-func (a *adapter) groupSettingsByTopic(ctx context.Context, topic string) (*t.GroupSettings, error) {
+func (a *adapter) groupSettingsByTopic(ctx context.Context, tenantID t.TenantID, topic string) (*t.GroupSettings, error) {
 	var item t.GroupSettings
-	err := a.db.QueryRowxContext(ctx, "SELECT "+groupSettingsSelectColumns+" FROM im_group_settings WHERE topic=?", topic).StructScan(&item)
+	err := a.db.QueryRowxContext(ctx, "SELECT "+groupSettingsSelectColumns+" FROM im_group_settings WHERE tenant_id=? AND topic=?", tenantID, topic).StructScan(&item)
 	if err == sql.ErrNoRows {
 		return nil, t.ErrNotFound
 	}
diff --git a/server/db/mysql/tenant_tables.go b/server/db/mysql/tenant_tables.go
index ab67567..4f1f0af 100644
--- a/server/db/mysql/tenant_tables.go
+++ b/server/db/mysql/tenant_tables.go
@@ -5,12 +5,16 @@ package mysql
 
 import (
 	"fmt"
+	"strings"
 
 	t "github.com/tinode/chat/server/store/types"
 )
 
 func tenantShardSQL(tenantID t.TenantID, query string) string {
-	return query
+	query = strings.ReplaceAll(query, "im_topics", tenantTopicsTable(tenantID))
+	query = strings.ReplaceAll(query, "im_group_members", tenantGroupMembersTable(tenantID))
+	query = strings.ReplaceAll(query, "im_subscriptions", tenantSubscriptionsTable(tenantID))
+	return strings.ReplaceAll(query, "im_system_notifications", tenantSystemNotificationsTable(tenantID))
 }
 
 func tenantTablePrefix(tenantID t.TenantID) string {
diff --git a/server/store/types/groups.go b/server/store/types/groups.go
index 342521e..53fec90 100644
--- a/server/store/types/groups.go
+++ b/server/store/types/groups.go
@@ -29,6 +29,7 @@ const (
 )
 
 type GroupSettings struct {
+	TenantID          TenantID   `db:"tenant_id"`
 	Topic             string     `db:"topic"`
 	OwnerUserID       Uid        `db:"-"`
 	Name              string     `db:"name"`