diff --git a/src/stm32f1/serial.c b/src/stm32f1/serial.c
index bc6ebb94..cfc5d04d 100644
--- a/src/stm32f1/serial.c
+++ b/src/stm32f1/serial.c
@@ -29,8 +29,8 @@ serial_init(void)
     LL_USART_SetHWFlowCtrl(USART1, LL_USART_HWCONTROL_NONE);
     LL_USART_SetTransferDirection(USART1, LL_USART_DIRECTION_TX_RX);
     LL_USART_EnableIT_RXNE(USART1);
+    NVIC_SetPriority(USART1_IRQn, 0);
     NVIC_EnableIRQ(USART1_IRQn);
-    NVIC_SetPriority(USART1_IRQn, 1);
     LL_USART_Enable(USART1);
 
     LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_GPIOA);
diff --git a/src/stm32f1/timer.c b/src/stm32f1/timer.c
index b0549136..e9b96b0a 100644
--- a/src/stm32f1/timer.c
+++ b/src/stm32f1/timer.c
@@ -8,7 +8,6 @@
 #include "autoconf.h"
 #include "board/misc.h" // timer_from_us
 #include "stm32f1xx.h"
-#include "stm32f1xx.h"
 #include "stm32f1xx_ll_bus.h"
 #include "stm32f1xx_ll_tim.h"
 #include "command.h" // shutdown
@@ -96,8 +95,8 @@ timer_init(void)
     LL_TIM_SetAutoReload(TIM2, 0xFFFF);
     LL_TIM_EnableIT_CC1(TIM2);
     LL_TIM_CC_EnableChannel(TIM2, LL_TIM_CHANNEL_CH1);
+    NVIC_SetPriority(TIM2_IRQn, 2);
     NVIC_EnableIRQ(TIM2_IRQn);
-    NVIC_SetPriority(TIM2_IRQn, 0);
     timer_kick();
     timer_reset();
     LL_TIM_EnableCounter(TIM2);