diff --git a/src/main/io/serial_1wire.c b/src/main/io/serial_1wire.c
index 5b2c09d5f..457dfb772 100644
--- a/src/main/io/serial_1wire.c
+++ b/src/main/io/serial_1wire.c
@@ -73,9 +73,6 @@ static void gpio_set_mode(GPIO_TypeDef* gpio, uint16_t pin, GPIO_Mode mode) {
   gpioInit(gpio, &cfg);
 }
 
-#ifdef STM32F10X
-static volatile uint32_t in_cr_mask, out_cr_mask;
-
 void usb1WireInitialize()
 {
    for (volatile uint8_t i = 0; i<ESC_COUNT ; i++){
@@ -83,6 +80,8 @@ void usb1WireInitialize()
    }
 }
 
+#ifdef STM32F10X
+static volatile uint32_t in_cr_mask, out_cr_mask;
 static __IO uint32_t *cr;
 static void gpio_prep_vars(uint16_t escIndex)
 {