diff --git a/tests/19-param-OK.asn1 b/tests/19-param-OK.asn1
index cd132d22d3a2f6d4520fadec433ad683d89e815e..31fa7721c30a7c1a36a7ea7f40545474f0b13248 100644
--- a/tests/19-param-OK.asn1
+++ b/tests/19-param-OK.asn1
@@ -14,7 +14,7 @@ BEGIN
 	SIGNED { ToBeSigned } ::= SEQUENCE {
 		toBeSigned	ToBeSigned,
 		algorithm	OBJECT IDENTIFIER,
-		signature	BIT STRING
+		signature	BIT STRING SIZE(0..256)
 	}
 
 	Certificate ::= SIGNED { SEQUENCE {
diff --git a/tests/19-param-OK.asn1.-EF b/tests/19-param-OK.asn1.-EF
index 8ece75ccef0295b51486ea72785d11510a984227..624041433c86d13523ea4395d7774ffede776e54 100644
--- a/tests/19-param-OK.asn1.-EF
+++ b/tests/19-param-OK.asn1.-EF
@@ -1,5 +1,5 @@
 
-ModuleTestParam {iso(-1) org(3) dod(6) internet(1) private(4)
+ModuleTestParam {iso org(3) dod(6) internet(1) private(4)
 	enterprise(1) spelio(9363) software(1) asn1c(5) test(1)
 	19 }
 DEFINITIONS ::=
@@ -8,7 +8,7 @@ BEGIN
 SIGNED{ToBeSigned} ::= SEQUENCE {
     toBeSigned	 ToBeSigned,
     algorithm	 OBJECT IDENTIFIER,
-    signature	 BIT STRING
+    signature	 BIT STRING SIZE(0..256)
 }
 
 Certificate ::= SEQUENCE {
@@ -18,7 +18,7 @@ Certificate ::= SEQUENCE {
         issuer	 Name
     },
     algorithm	 OBJECT IDENTIFIER,
-    signature	 BIT STRING
+    signature	 BIT STRING SIZE(0..256)
 }
 
 Name ::= SEQUENCE OF RelativeDistinguishedName
diff --git a/tests/19-param-OK.asn1.-P b/tests/19-param-OK.asn1.-P
index c40c439cce29a6420a05f5185acc9ebb53fe078e..c69a75bfec9becb44362410e25f58a91fdf988cb 100644
--- a/tests/19-param-OK.asn1.-P
+++ b/tests/19-param-OK.asn1.-P
@@ -30,6 +30,40 @@ typedef struct Certificate {
 	ber_dec_ctx_t _ber_dec_ctx;
 } Certificate_t;
 
+/*** <<< CODE [Certificate] >>> ***/
+
+static int
+memb_signature_1_constraint(asn1_TYPE_descriptor_t *td, const void *sptr,
+			asn_app_consume_bytes_f *app_errlog, void *app_key) {
+	const BIT_STRING_t *st = sptr;
+	size_t size;
+	
+	if(!sptr) {
+		_ASN_ERRLOG(app_errlog, app_key,
+			"%s: value not given (%s:%d)",
+			td->name, __FILE__, __LINE__);
+		return -1;
+	}
+	
+	if(st->size > 0) {
+		/* Size in bits */
+		size = 8 * (st->size - 1) - (st->buf[0] & 0x7);
+	} else {
+		size = 0;
+	}
+	
+	if((size <= 256)) {
+		/* Constraint check succeeded */
+		return 0;
+	} else {
+		_ASN_ERRLOG(app_errlog, app_key,
+			"%s: constraint failed (%s:%d)",
+			td->name, __FILE__, __LINE__);
+		return -1;
+	}
+}
+
+
 /*** <<< STAT-DEFS [Certificate] >>> ***/
 
 static asn1_TYPE_member_t asn1_MBR_toBeSigned[] = {
@@ -108,7 +142,7 @@ static asn1_TYPE_member_t asn1_MBR_Certificate[] = {
 		.tag = (ASN_TAG_CLASS_UNIVERSAL | (3 << 2)),
 		.tag_mode = 0,
 		.type = (void *)&asn1_DEF_BIT_STRING,
-		.memb_constraints = 0,	/* Defer to actual type */
+		.memb_constraints = memb_signature_1_constraint,
 		.name = "signature"
 		},
 };
@@ -116,7 +150,7 @@ static ber_tlv_tag_t asn1_DEF_Certificate_tags[] = {
 	(ASN_TAG_CLASS_UNIVERSAL | (16 << 2))
 };
 static asn1_TYPE_tag2member_t asn1_DEF_Certificate_tag2el[] = {
-    { (ASN_TAG_CLASS_UNIVERSAL | (3 << 2)), 2, 0, 0 }, /* signature at 18 */
+    { (ASN_TAG_CLASS_UNIVERSAL | (3 << 2)), 2, 0, 0 }, /* signature at 17 */
     { (ASN_TAG_CLASS_UNIVERSAL | (6 << 2)), 1, 0, 0 }, /* algorithm at 16 */
     { (ASN_TAG_CLASS_UNIVERSAL | (16 << 2)), 0, 0, 0 }, /* toBeSigned at 21 */
 };
@@ -255,7 +289,7 @@ static int check_permitted_alphabet_1(const void *sptr) {
 /*** <<< CODE [RelativeDistinguishedName] >>> ***/
 
 static int
-memb_IA5String_1_constraint(asn1_TYPE_descriptor_t *td, const void *sptr,
+memb_IA5String_2_constraint(asn1_TYPE_descriptor_t *td, const void *sptr,
 			asn_app_consume_bytes_f *app_errlog, void *app_key) {
 	const IA5String_t *st = sptr;
 	
@@ -286,7 +320,7 @@ static asn1_TYPE_member_t asn1_MBR_RelativeDistinguishedName[] = {
 		.tag = (ASN_TAG_CLASS_UNIVERSAL | (22 << 2)),
 		.tag_mode = 0,
 		.type = (void *)&asn1_DEF_IA5String,
-		.memb_constraints = memb_IA5String_1_constraint,
+		.memb_constraints = memb_IA5String_2_constraint,
 		.name = ""
 		},
 };