diff --git a/board/freescale/t4rdb/t4240rdb.c b/board/freescale/t4rdb/t4240rdb.c
index 0035bd7..ab71776 100644
--- a/board/freescale/t4rdb/t4240rdb.c
+++ b/board/freescale/t4rdb/t4240rdb.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright 2014 Freescale Semiconductor, Inc.
+ * Copyright 2023 NXP
  */
 
 #include <common.h>
@@ -20,6 +21,7 @@
 #include <asm/fsl_law.h>
 #include <asm/fsl_serdes.h>
 #include <asm/fsl_liodn.h>
+#include <clock_legacy.h>
 #include <fm_eth.h>
 
 #include "t4rdb.h"
@@ -28,6 +30,13 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#if CONFIG_IS_ENABLED(DM_SERIAL)
+int get_serial_clock(void)
+{
+	return get_bus_freq(0) / 2;
+}
+#endif
+
 int checkboard(void)
 {
 	struct cpu_type *cpu = gd->arch.cpu;
diff --git a/include/configs/T4240RDB.h b/include/configs/T4240RDB.h
index 506f1b7..78e1362 100644
--- a/include/configs/T4240RDB.h
+++ b/include/configs/T4240RDB.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Copyright 2014 Freescale Semiconductor, Inc.
- * Copyright 2020-2021 NXP
+ * Copyright 2020-2023 NXP
  */
 
 /*
@@ -77,7 +77,9 @@
  * open - index 2
  * shorted - index 1
  */
+#if !CONFIG_IS_ENABLED(DM_SERIAL)
 #define CFG_SYS_NS16550_CLK		(get_bus_freq(0)/2)
+#endif
 
 #define CFG_SYS_BAUDRATE_TABLE	\
 	{300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200}