diff --git a/usr.sbin/ndiscvt/inf.c b/usr.sbin/ndiscvt/inf.c
index fe4db6af5c7d..4b30da0a3024 100644
--- a/usr.sbin/ndiscvt/inf.c
+++ b/usr.sbin/ndiscvt/inf.c
@@ -887,6 +887,12 @@ regkey_add (const char *r)
 void
 push_word (const char *w)
 {
+
+	if (idx == W_MAX) {
+		fprintf(stderr, "too many words; try bumping W_MAX in inf.h\n");
+		exit(1);
+	}
+
 	if (w && strlen(w))
 		words[idx++] = w;
 	else
diff --git a/usr.sbin/ndiscvt/inf.h b/usr.sbin/ndiscvt/inf.h
index 8d0b0c123de4..ba08d674eeac 100644
--- a/usr.sbin/ndiscvt/inf.h
+++ b/usr.sbin/ndiscvt/inf.h
@@ -4,7 +4,7 @@
  * $FreeBSD$
  */
 
-#define W_MAX	16
+#define W_MAX	32
 
 struct section {
 	const char *	name;