diff --git a/src/runtime/virtcontainers/clh.go b/src/runtime/virtcontainers/clh.go
index 630054f85..50f34892d 100644
--- a/src/runtime/virtcontainers/clh.go
+++ b/src/runtime/virtcontainers/clh.go
@@ -286,11 +286,12 @@ func (clh *cloudHypervisor) createSandbox(ctx context.Context, id string, networ
 		clh.vmconfig.Pmem = &[]chclient.PmemConfig{*pmem}
 	}
 
-	// set the serial console to the cloud hypervisor
+	// Use serial port as the guest console only in debug mode,
+	// so that we can gather early OS booting log
 	if clh.config.Debug {
 		clh.vmconfig.Serial = chclient.NewConsoleConfig(cctTTY)
 	} else {
-		clh.vmconfig.Serial = chclient.NewConsoleConfig(cctNULL)
+		clh.vmconfig.Serial = chclient.NewConsoleConfig(cctOFF)
 	}
 
 	clh.vmconfig.Console = chclient.NewConsoleConfig(cctOFF)
@@ -967,9 +968,8 @@ func (clh *cloudHypervisor) launchClh() (int, error) {
 //###########################################################################
 
 const (
-	cctOFF  string = "Off"
-	cctNULL string = "Null"
-	cctTTY  string = "Tty"
+	cctOFF string = "Off"
+	cctTTY string = "Tty"
 )
 
 const (