diff --git a/skeletons/ber_tlv_length.h b/skeletons/ber_tlv_length.h
index 3496802..f7f95e5 100644
--- a/skeletons/ber_tlv_length.h
+++ b/skeletons/ber_tlv_length.h
@@ -32,7 +32,7 @@
  * 	Standard {-1,0,>0} convention.
  */
 ssize_t ber_skip_length(
-	struct asn_codec_ctx_s *opt_codec_ctx,	/* optional context */
+	const struct asn_codec_ctx_s *opt_codec_ctx,	/* optional context */
 	int _is_constructed, const void *bufptr, size_t size);
 
 /*