only do it in case of short strings

diff --git a/skeletons/BIT_STRING.c b/skeletons/BIT_STRING.c
index 4914b20..7727d78 100644
--- a/skeletons/BIT_STRING.c
+++ b/skeletons/BIT_STRING.c
@@ -78,7 +78,7 @@
 	 * Hexadecimal dump.
 	 */
 	for(buf++; buf < end; buf++) {
-		if(((buf - st->buf) - 1) % 16 == 0) {
+		if(((buf - st->buf) - 1) % 16 == 0 && (st->size > 16)) {
 			int i;
 			/* Indentation */
 			if(cb("\n", 1, app_key)) return -1;