diff --git a/lib/isc/tls.c b/lib/isc/tls.c
index 237f1dd52d..a8be0ac3f2 100644
--- a/lib/isc/tls.c
+++ b/lib/isc/tls.c
@@ -462,7 +462,7 @@ isc_tlsctx_createserver(const char *keyfile, const char *certfile,
 
 		X509_set_pubkey(cert, pkey);
 
-		X509_NAME *name = X509_get_subject_name(cert);
+		X509_NAME *name = X509_NAME_dup(X509_get_subject_name(cert));
 
 		X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC,
 					   (const unsigned char *)"AQ", -1, -1,
@@ -477,6 +477,9 @@ isc_tlsctx_createserver(const char *keyfile, const char *certfile,
 					   -1, -1, 0);
 
 		X509_set_issuer_name(cert, name);
+
+		X509_NAME_free(name);
+
 		X509_sign(cert, pkey, EVP_sha256());
 		rv = SSL_CTX_use_certificate(ctx, cert);
 		if (rv != 1) {