diff --git a/include/blk.h b/include/blk.h
index 1e8334c23a..fd545202eb 100644
--- a/include/blk.h
+++ b/include/blk.h
@@ -19,20 +19,23 @@ typedef ulong lbaint_t;
 #define LBAFU "%" LBAFlength "u"
 
 /* Interface types: */
-#define IF_TYPE_UNKNOWN		0
-#define IF_TYPE_IDE		1
-#define IF_TYPE_SCSI		2
-#define IF_TYPE_ATAPI		3
-#define IF_TYPE_USB		4
-#define IF_TYPE_DOC		5
-#define IF_TYPE_MMC		6
-#define IF_TYPE_SD		7
-#define IF_TYPE_SATA		8
-#define IF_TYPE_HOST		9
-#define IF_TYPE_MAX		10	/* Max number of IF_TYPE_* supported */
+enum if_type {
+	IF_TYPE_UNKNOWN = 0,
+	IF_TYPE_IDE,
+	IF_TYPE_SCSI,
+	IF_TYPE_ATAPI,
+	IF_TYPE_USB,
+	IF_TYPE_DOC,
+	IF_TYPE_MMC,
+	IF_TYPE_SD,
+	IF_TYPE_SATA,
+	IF_TYPE_HOST,
+
+	IF_TYPE_COUNT,			/* Number of interface types */
+};
 
 struct blk_desc {
-	int		if_type;	/* type of the interface */
+	enum if_type	if_type;	/* type of the interface */
 	int		dev;		/* device number */
 	unsigned char	part_type;	/* partition type */
 	unsigned char	target;		/* target SCSI ID */