Catch V_ASN1_NULL.
diff --git a/crypto/asn1/a_type.c b/crypto/asn1/a_type.c
index cf71602..e72a6b2 100644
--- a/crypto/asn1/a_type.c
+++ b/crypto/asn1/a_type.c
@@ -315,6 +315,8 @@
 		case V_ASN1_OBJECT:
 			ASN1_OBJECT_free(a->value.object);
 			break;
+		case V_ASN1_NULL:
+			break;
 		case V_ASN1_INTEGER:
 		case V_ASN1_NEG_INTEGER:
 		case V_ASN1_ENUMERATED: