diff --git a/skeletons/constr_SET_OF.h b/skeletons/constr_SET_OF.h
index bcd0966..75e18cf 100644
--- a/skeletons/constr_SET_OF.h
+++ b/skeletons/constr_SET_OF.h
@@ -11,7 +11,7 @@
 extern "C" {
 #endif
 
-typedef struct asn_SET_OF_specifics_s {
+typedef const struct asn_SET_OF_specifics_s {
 	/*
 	 * Target structure description.
 	 */