diff --git a/skeletons/oer_decoder.h b/skeletons/oer_decoder.h
index db6005f..bf4bc08 100644
--- a/skeletons/oer_decoder.h
+++ b/skeletons/oer_decoder.h
@@ -56,8 +56,8 @@
  */
 ssize_t oer_open_type_get(const asn_codec_ctx_t *opt_codec_ctx,
                           struct asn_TYPE_descriptor_s *td,
-                          asn_oer_constraints_t *constraints, void **struct_ptr,
-                          const void *bufptr, size_t size);
+                          const asn_oer_constraints_t *constraints,
+                          void **struct_ptr, const void *bufptr, size_t size);
 
 
 #ifdef __cplusplus