diff --git a/src/fan_ctrl_pwm.c b/src/fan_ctrl_pwm.c
index 30a8d2e..feb23c7 100644
--- a/src/fan_ctrl_pwm.c
+++ b/src/fan_ctrl_pwm.c
@@ -46,6 +46,7 @@ void fan_ctrl_pwm_enable(void)
 	gpio_set(DCDC_PORT, DCDC_BYPASS_SWITCH_PIN);
 
 	// Enable PWM output on the PWM GPIO
+	gpio_mode_setup(FAN_PORT, GPIO_MODE_AF, GPIO_PUPD_NONE, FAN_PWM_PIN);
 	gpio_set_af(FAN_PORT, GPIO_AF0, FAN_PWM_PIN);
 
 	// start the PWM timer
@@ -63,6 +64,7 @@ void fan_ctrl_pwm_disable(void)
 	timer_disable_counter(TIM21);
 
 	// configure the PWM GPIO as input so the fan runs full speed if powered
+	gpio_mode_setup(FAN_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, FAN_PWM_PIN);
 }