add skeleton OER stubs
diff --git a/skeletons/NULL.c b/skeletons/NULL.c
index fb21c75..d966827 100644
--- a/skeletons/NULL.c
+++ b/skeletons/NULL.c
@@ -30,6 +30,13 @@
NULL_decode_uper, /* Unaligned PER decoder */
NULL_encode_uper, /* Unaligned PER encoder */
#endif /* ASN_DISABLE_PER_SUPPORT */
+#ifdef ASN_DISABLE_OER_SUPPORT
+ 0,
+ 0,
+#else
+ 0,
+ 0,
+#endif /* ASN_DISABLE_OER_SUPPORT */
0, /* Use generic outmost tag fetcher */
asn_DEF_NULL_tags,
sizeof(asn_DEF_NULL_tags) / sizeof(asn_DEF_NULL_tags[0]),