diff --git a/fuzz/cert.cc b/fuzz/cert.cc
index 0bfcac4..79e1456 100644
--- a/fuzz/cert.cc
+++ b/fuzz/cert.cc
@@ -26,6 +26,10 @@
     uint8_t *der = NULL;
     i2d_X509(x509, &der);
     OPENSSL_free(der);
+
+    BIO *bio = BIO_new(BIO_s_mem());
+    X509_print(bio, x509);
+    BIO_free(bio);
   }
   X509_free(x509);
   ERR_clear_error();