diff --git a/crypto/asn1/a_object.c b/crypto/asn1/a_object.c
index 0fbc368f0db569ec3a051ad4603007db439872b0..a36356e34474e2b99b27683f124a57064a81f65b 100644
--- a/crypto/asn1/a_object.c
+++ b/crypto/asn1/a_object.c
@@ -246,6 +246,8 @@ int i2a_ASN1_OBJECT(BIO *bp, ASN1_OBJECT *a)
 			return -1;
 		i2t_ASN1_OBJECT(p,i + 1,a);
 		}
+	if (i <= 0)
+		return BIO_write(bp, "<INVALID>", 9);
 	BIO_write(bp,p,i);
 	if (p != buf)
 		OPENSSL_free(p);