diff --git a/tests/125-bitstring-constraint-OK.asn1.-P b/tests/125-bitstring-constraint-OK.asn1.-P
new file mode 100644
index 0000000..1ad8ef8
--- /dev/null
+++ b/tests/125-bitstring-constraint-OK.asn1.-P
@@ -0,0 +1,146 @@
+
+/*** <<< INCLUDES [T] >>> ***/
+
+#include <BIT_STRING.h>
+
+/*** <<< DEPS [T] >>> ***/
+
+typedef enum T {
+	T_flag1	= 0,
+	T_flag2	= 1,
+	T_flag3	= 2
+} e_T;
+
+/*** <<< TYPE-DECLS [T] >>> ***/
+
+typedef BIT_STRING_t	 T_t;
+
+/*** <<< FUNC-DECLS [T] >>> ***/
+
+extern asn_TYPE_descriptor_t asn_DEF_T;
+asn_struct_free_f T_free;
+asn_struct_print_f T_print;
+asn_constr_check_f T_constraint;
+ber_type_decoder_f T_decode_ber;
+der_type_encoder_f T_encode_der;
+xer_type_decoder_f T_decode_xer;
+xer_type_encoder_f T_encode_xer;
+
+/*** <<< CODE [T] >>> ***/
+
+int
+T_constraint(asn_TYPE_descriptor_t *td, const void *sptr,
+			asn_app_constraint_failed_f *ctfailcb, void *app_key) {
+	const BIT_STRING_t *st = (const BIT_STRING_t *)sptr;
+	
+	if(!sptr) {
+		_ASN_CTFAIL(app_key, td, sptr,
+			"%s: value not given (%s:%d)",
+			td->name, __FILE__, __LINE__);
+		return -1;
+	}
+	
+	
+	if(1 /* No applicable constraints whatsoever */) {
+		/* Nothing is here. See below */
+	}
+	
+	/* Replace with underlying type checker */
+	td->check_constraints = asn_DEF_BIT_STRING.check_constraints;
+	return td->check_constraints(td, sptr, ctfailcb, app_key);
+}
+
+/*
+ * This type is implemented using BIT_STRING,
+ * so here we adjust the DEF accordingly.
+ */
+static void
+T_1_inherit_TYPE_descriptor(asn_TYPE_descriptor_t *td) {
+	td->free_struct    = asn_DEF_BIT_STRING.free_struct;
+	td->print_struct   = asn_DEF_BIT_STRING.print_struct;
+	td->ber_decoder    = asn_DEF_BIT_STRING.ber_decoder;
+	td->der_encoder    = asn_DEF_BIT_STRING.der_encoder;
+	td->xer_decoder    = asn_DEF_BIT_STRING.xer_decoder;
+	td->xer_encoder    = asn_DEF_BIT_STRING.xer_encoder;
+	td->uper_decoder   = asn_DEF_BIT_STRING.uper_decoder;
+	td->uper_encoder   = asn_DEF_BIT_STRING.uper_encoder;
+	if(!td->per_constraints)
+		td->per_constraints = asn_DEF_BIT_STRING.per_constraints;
+	td->elements       = asn_DEF_BIT_STRING.elements;
+	td->elements_count = asn_DEF_BIT_STRING.elements_count;
+	td->specifics      = asn_DEF_BIT_STRING.specifics;
+}
+
+void
+T_free(asn_TYPE_descriptor_t *td,
+		void *struct_ptr, int contents_only) {
+	T_1_inherit_TYPE_descriptor(td);
+	td->free_struct(td, struct_ptr, contents_only);
+}
+
+int
+T_print(asn_TYPE_descriptor_t *td, const void *struct_ptr,
+		int ilevel, asn_app_consume_bytes_f *cb, void *app_key) {
+	T_1_inherit_TYPE_descriptor(td);
+	return td->print_struct(td, struct_ptr, ilevel, cb, app_key);
+}
+
+asn_dec_rval_t
+T_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+		void **structure, const void *bufptr, size_t size, int tag_mode) {
+	T_1_inherit_TYPE_descriptor(td);
+	return td->ber_decoder(opt_codec_ctx, td, structure, bufptr, size, tag_mode);
+}
+
+asn_enc_rval_t
+T_encode_der(asn_TYPE_descriptor_t *td,
+		void *structure, int tag_mode, ber_tlv_tag_t tag,
+		asn_app_consume_bytes_f *cb, void *app_key) {
+	T_1_inherit_TYPE_descriptor(td);
+	return td->der_encoder(td, structure, tag_mode, tag, cb, app_key);
+}
+
+asn_dec_rval_t
+T_decode_xer(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+		void **structure, const char *opt_mname, const void *bufptr, size_t size) {
+	T_1_inherit_TYPE_descriptor(td);
+	return td->xer_decoder(opt_codec_ctx, td, structure, opt_mname, bufptr, size);
+}
+
+asn_enc_rval_t
+T_encode_xer(asn_TYPE_descriptor_t *td, void *structure,
+		int ilevel, enum xer_encoder_flags_e flags,
+		asn_app_consume_bytes_f *cb, void *app_key) {
+	T_1_inherit_TYPE_descriptor(td);
+	return td->xer_encoder(td, structure, ilevel, flags, cb, app_key);
+}
+
+
+/*** <<< STAT-DEFS [T] >>> ***/
+
+static ber_tlv_tag_t asn_DEF_T_tags_1[] = {
+	(ASN_TAG_CLASS_UNIVERSAL | (3 << 2))
+};
+asn_TYPE_descriptor_t asn_DEF_T = {
+	"T",
+	"T",
+	T_free,
+	T_print,
+	T_constraint,
+	T_decode_ber,
+	T_encode_der,
+	T_decode_xer,
+	T_encode_xer,
+	0, 0,	/* No PER support, use "-gen-PER" to enable */
+	0,	/* Use generic outmost tag fetcher */
+	asn_DEF_T_tags_1,
+	sizeof(asn_DEF_T_tags_1)
+		/sizeof(asn_DEF_T_tags_1[0]), /* 1 */
+	asn_DEF_T_tags_1,	/* Same as above */
+	sizeof(asn_DEF_T_tags_1)
+		/sizeof(asn_DEF_T_tags_1[0]), /* 1 */
+	0,	/* No PER visible constraints */
+	0, 0,	/* Defined elsewhere */
+	0	/* No specifics */
+};
+