diff --git a/sys/ddb/db_input.c b/sys/ddb/db_input.c
index b8f407f7c99d..d97de6b0e4b3 100644
--- a/sys/ddb/db_input.c
+++ b/sys/ddb/db_input.c
@@ -60,7 +60,6 @@ static int	db_lhistlsize, db_lhistidx, db_lhistcur;
 static int	db_lhist_nlines;
 
 #define	CTRL(c)		((c) & 0x1f)
-#define	isspace(c)	((c) == ' ' || (c) == '\t')
 #define	BLANK		' '
 #define	BACKUP		'\b'