diff --git a/skeletons/BIT_STRING.c b/skeletons/BIT_STRING.c
index 19b6ff2..4914b20 100644
--- a/skeletons/BIT_STRING.c
+++ b/skeletons/BIT_STRING.c
@@ -66,6 +66,8 @@
 	uint8_t *end;
 	char *p = scratch;
 
+	(void)td;	/* Unused argument */
+
 	if(!st || !st->buf) return cb("<absent>", 8, app_key);
 
 	ilevel += 4;