diff --git a/src/s1ap/asn1c/asnGenFiles/NULL.h b/src/s1ap/asn1c/asnGenFiles/NULL.h
new file mode 100644
index 0000000..802d12c
--- /dev/null
+++ b/src/s1ap/asn1c/asnGenFiles/NULL.h
@@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 2003-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	ASN_TYPE_NULL_H
+#define	ASN_TYPE_NULL_H
+
+#include <asn_application.h>
+#include <BOOLEAN.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * The value of the NULL type is meaningless: see BOOLEAN if you want to
+ * carry true/false semantics.
+ */
+typedef int NULL_t;
+
+extern asn_TYPE_descriptor_t asn_DEF_NULL;
+extern asn_TYPE_operation_t asn_OP_NULL;
+
+asn_struct_print_f NULL_print;
+asn_struct_compare_f NULL_compare;
+der_type_encoder_f NULL_encode_der;
+xer_type_decoder_f NULL_decode_xer;
+xer_type_encoder_f NULL_encode_xer;
+oer_type_decoder_f NULL_decode_oer;
+oer_type_encoder_f NULL_encode_oer;
+per_type_decoder_f NULL_decode_uper;
+per_type_encoder_f NULL_encode_uper;
+per_type_decoder_f NULL_decode_aper;
+per_type_encoder_f NULL_encode_aper;
+asn_random_fill_f  NULL_random_fill;
+
+#define NULL_free	BOOLEAN_free
+#define NULL_decode_ber	BOOLEAN_decode_ber
+#define NULL_constraint	asn_generic_no_constraint
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* NULL_H */