diff --git a/readme.txt b/readme.txt
index 6c54adbb4..a2ced2c47 100644
--- a/readme.txt
+++ b/readme.txt
@@ -89,6 +89,7 @@
 *****************************************************************************
 
 *** 2.5.2 ***
+- FIX: Fixed serial port in STM32F3 discovery test case (bug #402).
 - FIX: Fixed add %i to chprintf (bug #401).
 - FIX: Fixed STM32F051 various (bug #400).
 - FIX: Fixed STM32F103 HSI configuration (bug #399).
diff --git a/testhal/STM32F30x/UART/main.c b/testhal/STM32F30x/UART/main.c
index 421105cb1..9d0bea53c 100644
--- a/testhal/STM32F30x/UART/main.c
+++ b/testhal/STM32F30x/UART/main.c
@@ -127,8 +127,8 @@ int main(void) {
    * Activates the serial driver 1, PA9 and PA10 are routed to USART1.
    */
   uartStart(&UARTD1, &uart_cfg_1);
-  palSetPadMode(GPIOA, 9, PAL_MODE_ALTERNATE(1));       /* USART1 TX.       */
-  palSetPadMode(GPIOA, 10, PAL_MODE_ALTERNATE(1));      /* USART1 RX.       */
+  palSetPadMode(GPIOA, 9, PAL_MODE_ALTERNATE(7));       /* USART1 TX.       */
+  palSetPadMode(GPIOA, 10, PAL_MODE_ALTERNATE(7));      /* USART1 RX.       */
 
   /*
    * Starts the transmission, it will be handled entirely in background.