diff --git a/os/hal/include/serial_usb.h b/os/hal/include/serial_usb.h
index b926b1a68..abf6313d0 100644
--- a/os/hal/include/serial_usb.h
+++ b/os/hal/include/serial_usb.h
@@ -179,6 +179,8 @@ typedef struct {
   usbep_t                   bulk_out;
   /**
    * @brief   Interrupt IN endpoint used for notifications.
+   * @note    If set to zero then the INT endpoint is assumed to be not
+   *          present, USB descriptors must be changed accordingly.
    */
   usbep_t                   int_in;
 } SerialUSBConfig;
diff --git a/os/hal/src/serial_usb.c b/os/hal/src/serial_usb.c
index f5392bdf6..dc0e803a8 100644
--- a/os/hal/src/serial_usb.c
+++ b/os/hal/src/serial_usb.c
@@ -218,7 +218,9 @@ void sduStart(SerialUSBDriver *sdup, const SerialUSBConfig *config) {
                 "invalid state");
   usbp->in_params[config->bulk_in - 1U]   = sdup;
   usbp->out_params[config->bulk_out - 1U] = sdup;
-  usbp->in_params[config->int_in - 1U]    = sdup;
+  if (config->int_in > 0U) {
+    usbp->in_params[config->int_in - 1U]  = sdup;
+  }
   sdup->config = config;
   sdup->state = SDU_READY;
   osalSysUnlock();
@@ -245,7 +247,9 @@ void sduStop(SerialUSBDriver *sdup) {
   /* Driver in stopped state.*/
   usbp->in_params[sdup->config->bulk_in - 1U]   = NULL;
   usbp->out_params[sdup->config->bulk_out - 1U] = NULL;
-  usbp->in_params[sdup->config->int_in - 1U]    = NULL;
+  if (sdup->config->int_in > 0U) {
+    usbp->in_params[sdup->config->int_in - 1U]  = NULL;
+  }
   sdup->state = SDU_STOP;
 
   /* Queues reset in order to signal the driver stop to the application.*/
diff --git a/readme.txt b/readme.txt
index 95881022e..d3fbe91a2 100644
--- a/readme.txt
+++ b/readme.txt
@@ -74,6 +74,8 @@
 *****************************************************************************
 
 *** 3.0.0p4 ***
+- HAL: Change to the Serial_USB driver, now the INT endpoint is no more
+       mandatory.
 - HAL: New DAC driver implementation for STM32F4xx.
 - HAL: Fixed STM32 RTC SSR Register Counts Down (bug #591).
 - HAL: Fixed STM32 RTC PRER Register not being set in init (bug #590).