diff --git a/soc/nuvoton/npcx/common/pinctrl_soc.h b/soc/nuvoton/npcx/common/pinctrl_soc.h
index 8f03faa82b7..36d7af83194 100644
--- a/soc/nuvoton/npcx/common/pinctrl_soc.h
+++ b/soc/nuvoton/npcx/common/pinctrl_soc.h
@@ -125,7 +125,7 @@ struct npcx_pinctrl {
 		struct npcx_psl_input psl_in;
 		uint16_t cfg_word;
 	} cfg;
-	struct {
+	struct __packed {
 		/** Indicates the current pinctrl type. */
 		enum npcx_pinctrl_type type :2;
 		/** Properties used for pinmuxing. */