diff --git a/bootloaders/riotboot_serial/Makefile.ci b/bootloaders/riotboot_serial/Makefile.ci
index e2184eae00..f77aecd2a5 100644
--- a/bootloaders/riotboot_serial/Makefile.ci
+++ b/bootloaders/riotboot_serial/Makefile.ci
@@ -1,3 +1,6 @@
 BOARD_INSUFFICIENT_MEMORY := \
+    frdm-kw41z \
+    pba-d-01-kw2x \
     phynode-kw41z \
+    usb-kw41z \
     #
diff --git a/sys/include/riotboot/bootloader_selection.h b/sys/include/riotboot/bootloader_selection.h
index 81f089a4e5..52ba313307 100644
--- a/sys/include/riotboot/bootloader_selection.h
+++ b/sys/include/riotboot/bootloader_selection.h
@@ -68,6 +68,18 @@ extern "C" {
 #define BTN_BOOTLOADER_INVERTED true
 #endif
 
+/** @brief LED pin for bootloader indication
+ *
+ * This pin (typically connected to a LED) will be toggled while the bootloader is active.
+ * It can be used to communicate the current bootloader state to the user.
+ */
+#if !defined(LED_BOOTLOADER_PIN) && defined(LED0_PIN) && !defined(LED_BOOTLOADER_NONE) || DOXYGEN
+#define LED_BOOTLOADER_PIN      LED0_PIN
+#define LED_BOOTLOADER_ON       LED0_ON     /**< Turn the bootloader LED on  */
+#define LED_BOOTLOADER_OFF      LED0_OFF    /**< Turn the bootloader LED off */
+#define LED_BOOTLOADER_TOGGLE   LED0_TOGGLE /**< Toggle the bootloader LED   */
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/sys/riotboot/serial.c b/sys/riotboot/serial.c
index 454a27ab92..502f204e9d 100644
--- a/sys/riotboot/serial.c
+++ b/sys/riotboot/serial.c
@@ -69,6 +69,18 @@ static inline bool _boot_pin(void)
 #endif
 }
 
+static inline void _boot_led_toggle(void)
+{
+#ifdef LED_BOOTLOADER_PIN
+    static unsigned count = RIOTBOOT_DELAY / 10;
+
+    if (--count == 0) {
+        count = RIOTBOOT_DELAY / 10;
+        LED_BOOTLOADER_TOGGLE;
+    }
+#endif
+}
+
 /* send 'hello' byte until we get enter bootloader byte or timeout */
 static bool _bootdelay(unsigned tries, volatile bool *boot_default)
 {
@@ -88,6 +100,7 @@ static bool _bootdelay(unsigned tries, volatile bool *boot_default)
         if (_boot_pin()) {
             return false;
         }
+        _boot_led_toggle();
     }
 
     return *boot_default;
@@ -238,6 +251,10 @@ int riotboot_serial_loader(void)
 #ifdef BTN_BOOTLOADER_PIN
     gpio_init(BTN_BOOTLOADER_PIN, BTN_BOOTLOADER_MODE);
 #endif
+#ifdef LED_BOOTLOADER_PIN
+    gpio_init(LED_BOOTLOADER_PIN, GPIO_OUT);
+    LED_BOOTLOADER_OFF;
+#endif
 
     uart_init(RIOTBOOT_UART_DEV, RIOTBOOT_UART_BAUDRATE,
               _uart_rx_cmd, (void *)&reading);
@@ -247,6 +264,10 @@ int riotboot_serial_loader(void)
         return -1;
     }
 
+#ifdef LED_BOOTLOADER_ON
+    LED_BOOTLOADER_ON;
+#endif
+
     while (1) {
 
         /* we can't use mutex in riotboot */