diff --git a/lib/stm32/common/iwdg_common_all.c b/lib/stm32/common/iwdg_common_all.c
index b1b00f70..cbb831b7 100644
--- a/lib/stm32/common/iwdg_common_all.c
+++ b/lib/stm32/common/iwdg_common_all.c
@@ -102,11 +102,11 @@ void iwdg_set_period_ms(uint32_t period)
 		prescale = PRESCALER_MAX;
 	}
 
-	while (iwdg_prescaler_busy());
+	IWDG_KR = IWDG_KR_START;
 	IWDG_KR = IWDG_KR_UNLOCK;
+	while (iwdg_prescaler_busy());
 	IWDG_PR = prescale;
 	while (iwdg_reload_busy());
-	IWDG_KR = IWDG_KR_UNLOCK;
 	IWDG_RLR = count & COUNT_MASK;
 	
 	/* Refresh counter after configuration is complete */