diff --git a/nil/internal/contracts/smart-account.go b/nil/internal/contracts/smart-account.go
index 766ce286f..e8f3a0306 100644
--- a/nil/internal/contracts/smart-account.go
+++ b/nil/internal/contracts/smart-account.go
@@ -12,5 +12,5 @@ func PrepareDefaultSmartAccountForOwnerCode(publicKey []byte) types.Code {
 	args, err := NewCallData(NameSmartAccount, "", publicKey)
 	check.PanicIfErr(err)
 
-	return append(smartAccountCode, args...)
+	return append(smartAccountCode.Clone(), args...)
 }
diff --git a/nil/services/synccommittee/prover/tracer/tracer_nild_test.go b/nil/services/synccommittee/prover/tracer/tracer_nild_test.go
index f22c8c814..411914dbd 100644
--- a/nil/services/synccommittee/prover/tracer/tracer_nild_test.go
+++ b/nil/services/synccommittee/prover/tracer/tracer_nild_test.go
@@ -49,7 +49,7 @@ func (s *TracerNildTestSuite) waitTwoBlocks() {
 
 func (s *TracerNildTestSuite) SetupSuite() {
 	nilserviceCfg := &nilservice.Config{
-		NShards:              5,
+		NShards:              3,
 		HttpUrl:              rpctest.GetSockPath(s.T()),
 		Topology:             collate.TrivialShardTopologyId,
 		CollatorTickPeriodMs: 100,
diff --git a/nil/tests/cometa/cometa_test.go b/nil/tests/cometa/cometa_test.go
index ee8feb337..8b309f098 100644
--- a/nil/tests/cometa/cometa_test.go
+++ b/nil/tests/cometa/cometa_test.go
@@ -69,6 +69,7 @@ func (s *SuiteCometaClickhouse) SetupSuite() {
 	s.cometaCfg.UseBadger = false
 
 	s.cometaCfg.ResetToDefault()
+	s.cometaCfg.DbEndpoint = "127.0.0.1:9002"
 
 	suiteSetupDone := false
 
@@ -78,13 +79,21 @@ func (s *SuiteCometaClickhouse) SetupSuite() {
 		}
 	}()
 
-	s.clickhouse = exec.Command("clickhouse", "server", "--", "--listen_host=0.0.0.0")
-	s.clickhouse.Dir = s.T().TempDir()
+	dir := s.T().TempDir()
+	s.clickhouse = exec.Command( //nolint:gosec
+		"clickhouse", "server", "--",
+		"--listen_host=0.0.0.0",
+		"--tcp_port=9002",
+		"--http_port=",
+		"--mysql_port=",
+		"--path="+dir,
+	)
+	s.clickhouse.Dir = dir
 	err := s.clickhouse.Start()
 	s.Require().NoError(err)
 
 	time.Sleep(1 * time.Second)
-	createDb := exec.Command("clickhouse-client", "--query", "CREATE DATABASE IF NOT EXISTS "+s.cometaCfg.DbName) //nolint:gosec
+	createDb := exec.Command("clickhouse-client", "--port=9002", "--query", "CREATE DATABASE IF NOT EXISTS "+s.cometaCfg.DbName) //nolint:gosec
 	out, err := createDb.CombinedOutput()
 	s.Require().NoErrorf(err, "output: %s", out)
 
diff --git a/nil/tests/journald_forwarder/journald_forwarder_test.go b/nil/tests/journald_forwarder/journald_forwarder_test.go
index 17cfd5d2c..3c85652ce 100644
--- a/nil/tests/journald_forwarder/journald_forwarder_test.go
+++ b/nil/tests/journald_forwarder/journald_forwarder_test.go
@@ -43,13 +43,20 @@ func (s *SuiteJournaldForwarder) SetupSuite() {
 		}
 	}()
 
-	s.clickhouse = exec.Command("clickhouse", "server")
-	s.clickhouse.Dir = s.T().TempDir()
+	dir := s.T().TempDir()
+	s.clickhouse = exec.Command( //nolint:gosec
+		"clickhouse", "server", "--",
+		"--tcp_port=9001",
+		"--http_port=",
+		"--mysql_port=",
+		"--path="+dir,
+	)
+	s.clickhouse.Dir = dir
 	err := s.clickhouse.Start()
 	s.Require().NoError(err)
 
 	s.cfg = journald_forwarder.Config{
-		ListenAddr: "127.0.0.1:5678", ClickhouseAddr: "127.0.0.1:9000", DbUser: "default",
+		ListenAddr: "127.0.0.1:5678", ClickhouseAddr: "127.0.0.1:9001", DbUser: "default",
 		DbDatabase: "default", DbPassword: "",
 	}
 	s.runErrCh = make(chan error, 1)
diff --git a/nil/tests/ports.txt b/nil/tests/ports.txt
new file mode 100644
index 000000000..e8407af8f
--- /dev/null
+++ b/nil/tests/ports.txt
@@ -0,0 +1,4 @@
+# List all ports reserved by tests for different purposes
+
+nil/tests/journald_forwarder: 9001 (clickhouse)
+nil/tests/cometa: 9002 (clickhouse)