diff --git a/arch/arm/include/stm32l4/chip.h b/arch/arm/include/stm32l4/chip.h
index 12d7187640..9d0712b276 100644
--- a/arch/arm/include/stm32l4/chip.h
+++ b/arch/arm/include/stm32l4/chip.h
@@ -77,7 +77,7 @@
 #  define STM32L4_NBTIM                    2   /* Two basic timers, TIM6-7 */
 #  define STM32L4_NLPTIM                   2   /* Two low-power timers, LPTIM1-2 */
 #  define STM32L4_NRNG                     1   /* Random number generator (RNG) */
-#  define STM32L4_NUART                    4   /* UART 4-5 */
+#  define STM32L4_NUART                    2   /* UART 4-5 */
 #  define STM32L4_NUSART                   3   /* USART 1-3 */
 #  define STM32L4_NLPUART                  1   /* LPUART 1 */
 #  define STM32L4_NSPI                     3   /* SPI1-3 */
diff --git a/arch/arm/src/stm32l4/Kconfig b/arch/arm/src/stm32l4/Kconfig
index 6995a51421..9f8d6cbda1 100644
--- a/arch/arm/src/stm32l4/Kconfig
+++ b/arch/arm/src/stm32l4/Kconfig
@@ -44,6 +44,8 @@ config STM32L4_STM32L476XX
 	select ARCH_HAVE_DPFPU # REVISIT
 	select ARMV7M_HAVE_ITCM
 	select ARMV7M_HAVE_DTCM
+	select STM32L4_HAVE_USART1
+	select STM32L4_HAVE_USART2
 	select STM32L4_HAVE_USART3
 	select STM32L4_HAVE_UART4
 	select STM32L4_HAVE_UART5
@@ -55,6 +57,8 @@ config STM32L4_STM32L486XX
 	select ARCH_HAVE_DPFPU # REVISIT
 	select ARMV7M_HAVE_ITCM
 	select ARMV7M_HAVE_DTCM
+	select STM32L4_HAVE_USART1
+	select STM32L4_HAVE_USART2
 	select STM32L4_HAVE_USART3
 	select STM32L4_HAVE_UART4
 	select STM32L4_HAVE_UART5
@@ -408,15 +412,17 @@ config STM32L4_SPI3
 config STM32L4_USART1
 	bool "USART1"
 	default n
-	select USART1_SERIALDRIVER
+	depends on STM32L4_HAVE_USART1
 	select ARCH_HAVE_SERIAL_TERMIOS
+	select USART1_SERIALDRIVER
 	select STM32L4_USART
 
 config STM32L4_USART2
 	bool "USART2"
 	default n
-	select USART2_SERIALDRIVER
+	depends on STM32L4_HAVE_USART2
 	select ARCH_HAVE_SERIAL_TERMIOS
+	select USART2_SERIALDRIVER
 	select STM32L4_USART
 
 config STM32L4_USART3
@@ -2517,6 +2523,14 @@ config STM32L4_DAC_DMA_BUFFER_SIZE
 
 endmenu
 
+config STM32L4_HAVE_USART1
+	bool
+	default n
+
+config STM32L4_HAVE_USART2
+	bool
+	default n
+
 config STM32L4_HAVE_USART3
 	bool
 	default n
diff --git a/arch/arm/src/stm32l4/stm32l4_serial.c b/arch/arm/src/stm32l4/stm32l4_serial.c
index 8e4b8d3bee..dfef76a9b1 100644
--- a/arch/arm/src/stm32l4/stm32l4_serial.c
+++ b/arch/arm/src/stm32l4/stm32l4_serial.c
@@ -731,7 +731,7 @@ static struct stm32l4_serial_s g_uart5priv =
 
 /* This table lets us iterate over the configured USARTs */
 
-FAR static struct stm32l4_serial_s * const uart_devs[STM32L4_NUSART] =
+FAR static struct stm32l4_serial_s * const uart_devs[STM32L4_NUSART+STM32L4_NUART] =
 {
 #ifdef CONFIG_STM32L4_USART1
   [0] = &g_usart1priv,
@@ -2407,7 +2407,7 @@ void up_earlyserialinit(void)
 
   /* Disable all USART interrupts */
 
-  for (i = 0; i < STM32L4_NUSART; i++)
+  for (i = 0; i < STM32L4_NUSART+STM32L4_NUART; i++)
     {
       if (uart_devs[i])
         {
@@ -2476,7 +2476,7 @@ void up_serialinit(void)
 
   strcpy(devname, "/dev/ttySx");
 
-  for (i = 0; i < STM32L4_NUSART; i++)
+  for (i = 0; i < STM32L4_NUSART+STM32L4_NUART; i++)
     {
       /* Don't create a device for non-configured ports. */
 
diff --git a/arch/arm/src/stm32l4/stm32l4_uart.h b/arch/arm/src/stm32l4/stm32l4_uart.h
index 24fc9bd313..e66302d8e4 100644
--- a/arch/arm/src/stm32l4/stm32l4_uart.h
+++ b/arch/arm/src/stm32l4/stm32l4_uart.h
@@ -57,19 +57,19 @@
  * device.
  */
 
-#if STM32L4_NUSART < 5 || !defined(CONFIG_STM32L4_HAVE_UART5)
+#if !defined(CONFIG_STM32L4_HAVE_UART5)
 #  undef CONFIG_STM32L4_UART5
 #endif
-#if STM32L4_NUSART < 4 || !defined(CONFIG_STM32L4_HAVE_UART4)
+#if !defined(CONFIG_STM32L4_HAVE_UART4)
 #  undef CONFIG_STM32L4_UART4
 #endif
-#if STM32L4_NUSART < 3 || !defined(CONFIG_STM32L4_HAVE_USART3)
+#if !defined(CONFIG_STM32L4_HAVE_USART3)
 #  undef CONFIG_STM32L4_USART3
 #endif
-#if STM32L4_NUSART < 2
+#if !defined(CONFIG_STM32L4_HAVE_USART2)
 #  undef CONFIG_STM32L4_USART2
 #endif
-#if STM32L4_NUSART < 1
+#if !defined(CONFIG_STM32L4_HAVE_USART1)
 #  undef CONFIG_STM32L4_USART1
 #endif
 
diff --git a/configs/nucleo-l476rg/include/board.h b/configs/nucleo-l476rg/include/board.h
index 103f5a2e00..490e5af968 100644
--- a/configs/nucleo-l476rg/include/board.h
+++ b/configs/nucleo-l476rg/include/board.h
@@ -102,6 +102,9 @@
 #define GPIO_USART2_RTS  GPIO_USART2_RTS_2
 #define GPIO_USART2_CTS  GPIO_USART2_CTS_2
 
+#define GPIO_UART4_RX   GPIO_UART4_RX_1    /* PA1 */
+#define GPIO_UART4_TX   GPIO_UART4_TX_1    /* PA0 */
+
 /* I2C
  *
  * The optional _GPIO configurations allow the I2C driver to manually