diff --git a/Tools/AP_Periph/AP_Periph.cpp b/Tools/AP_Periph/AP_Periph.cpp
index 976dbc5834..b952d7ae24 100644
--- a/Tools/AP_Periph/AP_Periph.cpp
+++ b/Tools/AP_Periph/AP_Periph.cpp
@@ -608,7 +608,9 @@ void AP_Periph_FW::prepare_reboot()
 
         // delay to give the ACK a chance to get out, the LEDs to flash,
         // the IO board safety to be forced on, the parameters to flush,
+        hal.scheduler->expect_delay_ms(100);
         hal.scheduler->delay(40);
+        hal.scheduler->expect_delay_ms(0);
 }
 
 /*
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.c b/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.c
index c1a5eeb049..689f9e4acc 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.c
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.c
@@ -22,6 +22,16 @@
 #error "Unsupported IWDG RCC MCU config"
 #endif
 
+/*
+  define for controlling how long the watchdog is set for.
+*/
+#ifndef STM32_WDG_TIMEOUT_MS
+#define STM32_WDG_TIMEOUT_MS 2048
+#endif
+#if STM32_WDG_TIMEOUT_MS > 4096 || STM32_WDG_TIMEOUT_MS < 20
+#error "Watchdog timeout out of range"
+#endif
+
 /*
   defines for working out if the reset was from the watchdog
  */
@@ -68,16 +78,17 @@ static bool watchdog_enabled;
  */
 void stm32_watchdog_init(void)
 {
-    // setup for 2s reset
+    // setup the watchdog timeout
+    // t = 4 * 2^PR * (RLR+1) / 32KHz
     IWDGD.KR = 0x5555;
-    IWDGD.PR = 2; // div16
-    IWDGD.RLR = 0xFFF;
+    IWDGD.PR = 3; // changing this would change the definition of STM32_WDG_TIMEOUT_MS
+    IWDGD.RLR = STM32_WDG_TIMEOUT_MS - 1;
     IWDGD.KR = 0xCCCC;
     watchdog_enabled = true;
 }
 
 /*
-  pat the dog, to prevent a reset. If not called for 1s
+  pat the dog, to prevent a reset. If not called for STM32_WDG_TIMEOUT_MS
   after stm32_watchdog_init() then MCU will reset
  */
 void stm32_watchdog_pat(void)
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.h b/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.h
index f015dee9c1..de8e394149 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.h
@@ -10,7 +10,7 @@ extern "C" {
 void stm32_watchdog_init(void);
 
 /*
-  pat the dog, to prevent a reset. If not called for 1s
+  pat the dog, to prevent a reset. If not called for STM32_WDG_TIMEOUT_MS
   after stm32_watchdog_init() then MCU will reset
  */
 void stm32_watchdog_pat(void);