diff --git a/libasn1parser/asn1p_constr.c b/libasn1parser/asn1p_constr.c
index 7aa464e..ee8d1eb 100644
--- a/libasn1parser/asn1p_constr.c
+++ b/libasn1parser/asn1p_constr.c
@@ -169,6 +169,8 @@
 		return "MultipleTypeConstraints";
 	case ACT_CT_CTDBY:
 		return "UserDefinedConstraint";
+	case ACT_CT_CTNG:
+		return "ContentsConstraint";
 	case ACT_CA_SET:
 		return "SET";
 	case ACT_CA_CRC: