diff --git a/lib/zebra.h b/lib/zebra.h
index 00d422cdd1..b2f0202c53 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -360,6 +360,8 @@ typedef enum {
 	AFI_MAX = 4
 } afi_t;
 
+#define IS_VALID_AFI(a) ((a) > AFI_UNSPEC && (a) < AFI_MAX)
+
 /* Subsequent Address Family Identifier. */
 typedef enum {
 	SAFI_UNSPEC = 0,