diff --git a/os/hal/ports/NUMICRO/LLD/SERIALv1/hal_serial_lld.c b/os/hal/ports/NUMICRO/LLD/SERIALv1/hal_serial_lld.c
index bed98025..f3086c30 100644
--- a/os/hal/ports/NUMICRO/LLD/SERIALv1/hal_serial_lld.c
+++ b/os/hal/ports/NUMICRO/LLD/SERIALv1/hal_serial_lld.c
@@ -306,6 +306,9 @@ OSAL_IRQ_HANDLER(NUC123_UART1_HANDLER)
  */
 void sd_lld_init(void)
 {
+#if NUC123_SERIAL_USE_UART0 || NUC123_SERIAL_USE_UART1
+  CLK->CLKSEL1 = (CLK->CLKSEL1 & ~(CLK_CLKSEL1_UART_S_Msk)) | NUC123_SERIAL_CLKSRC;
+#endif
 
 #if NUC123_SERIAL_USE_UART0
   sdObjectInit(&SD0, NULL, notify0);
@@ -350,7 +353,6 @@ void sd_lld_start(SerialDriver* sdp, const SerialConfig* config)
 #if NUC123_SERIAL_USE_UART0
     if (&SD0 == sdp) {
       CLK->APBCLK |= CLK_APBCLK_UART0_EN_Msk;
-      CLK->CLKSEL1 = (CLK->CLKSEL1 & ~(CLK_CLKSEL1_UART_S_Msk)) | NUC123_SERIAL_CLKSRC;
       nvicEnableVector(NUC123_UART0_NUMBER, NUC123_SERIAL_UART0_IRQ_PRIORITY);
       SYS->IPRSTC2 |= SYS_IPRSTC2_UART0_RST_Msk;
       SYS->IPRSTC2 &= ~(SYS_IPRSTC2_UART0_RST_Msk);