change quotes
diff --git a/skeletons/constraints.c b/skeletons/constraints.c
index 1bdda73..6c8287a 100644
--- a/skeletons/constraints.c
+++ b/skeletons/constraints.c
@@ -1,5 +1,5 @@
-#include "asn_internal.h"
-#include "constraints.h"
+#include <asn_internal.h>
+#include <constraints.h>
 
 int
 asn_generic_no_constraint(asn_TYPE_descriptor_t *type_descriptor,