diff --git a/fuzz/asn1.c b/fuzz/asn1.c
index 69978cd054..ee602a08a3 100644
--- a/fuzz/asn1.c
+++ b/fuzz/asn1.c
@@ -317,8 +317,9 @@ int FuzzerTestOneInput(const uint8_t *buf, size_t len)
                 ASN1_item_print(bio, o, 4, i, pctx);
                 BIO_free(bio);
             }
-            ASN1_item_i2d(o, &der, i);
-            OPENSSL_free(der);
+            if (ASN1_item_i2d(o, &der, i) > 0) {
+                OPENSSL_free(der);
+            }
             ASN1_item_free(o, i);
         }
     }