diff --git a/bin/tests/system/checkconf/bad-doh-duplicates.conf b/bin/tests/system/checkconf/bad-doh-duplicates.conf
new file mode 100644
index 0000000000..dfb68b9b79
--- /dev/null
+++ b/bin/tests/system/checkconf/bad-doh-duplicates.conf
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+tls local-tls {
+	key-file "key.pem";
+	cert-file "cert.pem";
+};
+
+http local-http-server {
+	endpoints { "/dns-query"; };
+	listener-clients 100;
+	streams-per-connection 100;
+};
+
+# duplicated HTTP configuration
+http local-http-server {
+	endpoints { "/dns-query"; };
+	listener-clients 100;
+	streams-per-connection 100;
+};
+
+options {
+	listen-on { 10.53.0.1; };
+	http-port 80;
+	https-port 443;
+	http-listener-clients 100;
+	http-streams-per-connection 100;
+	listen-on port 443 tls local-tls http local-http-server { 10.53.0.1; };
+	listen-on port 8080 tls none http local-http-server { 10.53.0.1; };
+};
diff --git a/lib/bind9/check.c b/lib/bind9/check.c
index dda98d921e..88dcc4d73c 100644
--- a/lib/bind9/check.c
+++ b/lib/bind9/check.c
@@ -2031,23 +2031,22 @@ bind9_check_parentalagentlists(const cfg_obj_t *cctx, isc_log_t *logctx,
 #if HAVE_LIBNGHTTP2
 static isc_result_t
 bind9_check_httpserver(const cfg_obj_t *http, isc_log_t *logctx,
-		       isc_symtab_t *symtab, isc_mem_t *mctx) {
+		       isc_symtab_t *symtab) {
 	isc_result_t result, tresult;
 	const char *name = cfg_obj_asstring(cfg_map_getname(http));
-	char *tmp = isc_mem_strdup(mctx, name);
 	const cfg_obj_t *eps = NULL;
 	const cfg_listelt_t *elt = NULL;
 	isc_symvalue_t symvalue;
 
 	/* Check for duplicates */
 	symvalue.as_cpointer = http;
-	result = isc_symtab_define(symtab, tmp, 1, symvalue,
+	result = isc_symtab_define(symtab, name, 1, symvalue,
 				   isc_symexists_reject);
 	if (result == ISC_R_EXISTS) {
 		const char *file = NULL;
 		unsigned int line;
 
-		tresult = isc_symtab_lookup(symtab, tmp, 1, &symvalue);
+		tresult = isc_symtab_lookup(symtab, name, 1, &symvalue);
 		RUNTIME_CHECK(tresult == ISC_R_SUCCESS);
 
 		line = cfg_obj_line(symvalue.as_cpointer);
@@ -2061,7 +2060,6 @@ bind9_check_httpserver(const cfg_obj_t *http, isc_log_t *logctx,
 			    "also defined at %s:%u",
 			    name, file, line);
 	}
-	isc_mem_free(mctx, tmp);
 
 	/* Check endpoints are valid */
 	tresult = cfg_map_get(http, "endpoints", &eps);
@@ -2106,7 +2104,7 @@ bind9_check_httpservers(const cfg_obj_t *config, isc_log_t *logctx,
 
 	for (elt = cfg_list_first(obj); elt != NULL; elt = cfg_list_next(elt)) {
 		obj = cfg_listelt_value(elt);
-		tresult = bind9_check_httpserver(obj, logctx, symtab, mctx);
+		tresult = bind9_check_httpserver(obj, logctx, symtab);
 		if (result == ISC_R_SUCCESS) {
 			result = tresult;
 		}