diff --git a/targets/TARGET_STM/TARGET_STM32L4/serial_device.c b/targets/TARGET_STM/TARGET_STM32L4/serial_device.c
index 8bc710070a..4a9bfbf530 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/serial_device.c
+++ b/targets/TARGET_STM/TARGET_STM32L4/serial_device.c
@@ -491,7 +491,7 @@ static IRQn_Type serial_get_irq_n(serial_t *obj)
             irq_n = USART2_IRQn;
             break;
 
-#if defined(UART3_BASE)
+#if defined(USART3_BASE)
         case 2:
             irq_n = USART3_IRQn;
             break;