diff --git a/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c b/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c
index 20b9f5d810ec..f12e91cc4fcf 100644
--- a/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c
+++ b/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c
@@ -11,7 +11,7 @@
 #include "mt8186-afe-common.h"
 #include "mt8186-afe-gpio.h"
 
-struct pinctrl *aud_pinctrl;
+static struct pinctrl *aud_pinctrl;
 
 enum mt8186_afe_gpio {
 	MT8186_AFE_GPIO_CLK_MOSI_OFF,