diff --git a/Marlin/src/HAL/HAL_STM32F1/fastio_STM32F1.h b/Marlin/src/HAL/HAL_STM32F1/fastio_STM32F1.h
index 4c28571b36..31c59e00e2 100644
--- a/Marlin/src/HAL/HAL_STM32F1/fastio_STM32F1.h
+++ b/Marlin/src/HAL/HAL_STM32F1/fastio_STM32F1.h
@@ -30,7 +30,7 @@
 #include <libmaple/gpio.h>
 
 #define READ(IO)              (PIN_MAP[IO].gpio_device->regs->IDR & (1U << PIN_MAP[IO].gpio_bit) ? HIGH : LOW)
-#define WRITE(IO,V)           (PIN_MAP[IO].gpio_device->regs->BSRR = (1U << PIN_MAP[IO].gpio_bit) << (16 * !(bool)V))
+#define WRITE(IO,V)           (PIN_MAP[IO].gpio_device->regs->BSRR = (1U << PIN_MAP[IO].gpio_bit) << (16 * !((bool)V)))
 #define TOGGLE(IO)            (PIN_MAP[IO].gpio_device->regs->ODR = PIN_MAP[IO].gpio_device->regs->ODR ^ (1U << PIN_MAP[IO].gpio_bit))
 #define WRITE_VAR(IO,V)       WRITE(IO,V)