diff --git a/skeletons/RELATIVE-OID.c b/skeletons/RELATIVE-OID.c
index 008847a..82850f1 100644
--- a/skeletons/RELATIVE-OID.c
+++ b/skeletons/RELATIVE-OID.c
@@ -150,7 +150,7 @@
 }
 
 asn_dec_rval_t
-RELATIVE_OID_decode_xer(asn_codec_ctx_t *opt_codec_ctx,
+RELATIVE_OID_decode_xer(const asn_codec_ctx_t *opt_codec_ctx,
 	asn_TYPE_descriptor_t *td, void **sptr, const char *opt_mname,
 		const void *buf_ptr, size_t size) {