diff --git a/sys/dev/mii/mii.h b/sys/dev/mii/mii.h
index 297ef21aad26..fa1ec84eaa77 100644
--- a/sys/dev/mii/mii.h
+++ b/sys/dev/mii/mii.h
@@ -204,7 +204,7 @@
 #define	MII_PSESR	0x0c	/* PSE status register */
 #define	PSESR_PWRDENIED	0x1000	/* Power Denied */
 #define	PSESR_VALSIG	0x0800	/* Valid PD signature detected */
-#define	PSESR_INVALSIG	0x0400	/* Inalid PD signature detected */
+#define	PSESR_INVALSIG	0x0400	/* Invalid PD signature detected */
 #define	PSESR_SHORTCIRC	0x0200	/* Short circuit condition detected */
 #define	PSESR_OVERLOAD	0x0100	/* Overload condition detected */
 #define	PSESR_MPSABSENT	0x0080	/* MPS absent condition detected */