diff --git a/sys/net/netmap/netmap.c b/sys/net/netmap/netmap.c
--- a/sys/net/netmap/netmap.c
+++ b/sys/net/netmap/netmap.c
@@ -323,6 +323,7 @@
 nm_dump_buf(char *p, int len, int lim, char *dst)
 {
 	static char _dst[8192];
+#define NM_DUMP_MAXLEN	8192
 	int i, j, i0;
 	static char hex[] ="0123456789abcdef";
 	char *o;	/* output position */