diff --git a/crypto/asn1/tasn_enc.c b/crypto/asn1/tasn_enc.c
index cc87d349..d89ec8a7 100644
--- a/crypto/asn1/tasn_enc.c
+++ b/crypto/asn1/tasn_enc.c
@@ -583,6 +583,8 @@ int asn1_ex_i2c(ASN1_VALUE **pval, unsigned char *cout, int *putype,
         otmp = (ASN1_OBJECT *)*pval;
         cont = otmp->data;
         len = otmp->length;
+        if (cont == NULL || len == 0)
+            return -1;
         break;
 
     case V_ASN1_NULL: