diff --git a/src/feature/relay/circuitbuild_relay.c b/src/feature/relay/circuitbuild_relay.c
index 75b2767b82..b89866b477 100644
--- a/src/feature/relay/circuitbuild_relay.c
+++ b/src/feature/relay/circuitbuild_relay.c
@@ -251,7 +251,7 @@ STATIC const tor_addr_port_t *
 circuit_choose_ip_ap_for_extend(const tor_addr_port_t *ipv4_ap,
                                 const tor_addr_port_t *ipv6_ap)
 {
-  const bool ipv6_supported = router_has_advertised_ipv6_orport(get_options());
+  const bool ipv6_supported = router_can_extend_over_ipv6(get_options());
 
   /* If IPv6 is not supported, we can't use the IPv6 address. */
   if (!ipv6_supported) {
diff --git a/src/feature/relay/router.c b/src/feature/relay/router.c
index b0a56012db..2858371af5 100644
--- a/src/feature/relay/router.c
+++ b/src/feature/relay/router.c
@@ -1491,14 +1491,23 @@ router_get_advertised_ipv6_or_ap(const or_options_t *options,
 }
 
 /** Returns true if this router has an advertised IPv6 ORPort. */
-MOCK_IMPL(bool,
-router_has_advertised_ipv6_orport,(const or_options_t *options))
+bool
+router_has_advertised_ipv6_orport(const or_options_t *options)
 {
   tor_addr_port_t ipv6_ap;
   router_get_advertised_ipv6_or_ap(options, &ipv6_ap);
   return tor_addr_port_is_valid_ap(&ipv6_ap, 0);
 }
 
+/** Returns true if this router has an advertised IPv6 ORPort. */
+MOCK_IMPL(bool,
+router_can_extend_over_ipv6,(const or_options_t *options))
+{
+  /* We might add some extra checks here, such as ExtendAllowIPv6Addresses
+  * from ticket 33818. */
+  return router_has_advertised_ipv6_orport(options);
+}
+
 /** Return the port that we should advertise as our DirPort;
  * this is one of three possibilities:
  * The one that is passed as <b>dirport</b> if the DirPort option is 0, or
diff --git a/src/feature/relay/router.h b/src/feature/relay/router.h
index 1a262a6799..39c550dd25 100644
--- a/src/feature/relay/router.h
+++ b/src/feature/relay/router.h
@@ -68,8 +68,8 @@ uint16_t router_get_active_listener_port_by_type_af(int listener_type,
 uint16_t router_get_advertised_or_port(const or_options_t *options);
 void router_get_advertised_ipv6_or_ap(const or_options_t *options,
                                       tor_addr_port_t *ipv6_ap_out);
-MOCK_DECL(bool, router_has_advertised_ipv6_orport,(
-                                             const or_options_t *options));
+bool router_has_advertised_ipv6_orport(const or_options_t *options);
+MOCK_DECL(bool, router_can_extend_over_ipv6,(const or_options_t *options));
 uint16_t router_get_advertised_or_port_by_af(const or_options_t *options,
                                              sa_family_t family);
 uint16_t router_get_advertised_dir_port(const or_options_t *options,
diff --git a/src/test/test_circuitbuild.c b/src/test/test_circuitbuild.c
index ed75d102b9..03fd176ead 100644
--- a/src/test/test_circuitbuild.c
+++ b/src/test/test_circuitbuild.c
@@ -821,14 +821,14 @@ test_circuit_extend_lspec_valid(void *arg)
   tor_free(p_chan);
 }
 
-static bool router_has_ipv6_orport_result = false;
-static int mock_router_ipv6_orport_calls = 0;
+static bool can_extend_over_ipv6_result = false;
+static int mock_router_can_extend_over_ipv6_calls = 0;
 static bool
-mock_router_has_advertised_ipv6_orport(const or_options_t *options)
+mock_router_can_extend_over_ipv6(const or_options_t *options)
 {
   (void)options;
-  mock_router_ipv6_orport_calls++;
-  return router_has_ipv6_orport_result;
+  mock_router_can_extend_over_ipv6_calls++;
+  return can_extend_over_ipv6_result;
 }
 
 /* Test the different cases in circuit_choose_ip_ap_for_extend(). */
@@ -849,65 +849,65 @@ test_circuit_choose_ip_ap_for_extend(void *arg)
   MOCK(get_options, mock_get_options);
   mocked_options = fake_options;
 
-  MOCK(router_has_advertised_ipv6_orport,
-       mock_router_has_advertised_ipv6_orport);
-  router_has_ipv6_orport_result = true;
-  mock_router_ipv6_orport_calls = 0;
+  MOCK(router_can_extend_over_ipv6,
+       mock_router_can_extend_over_ipv6);
+  can_extend_over_ipv6_result = true;
+  mock_router_can_extend_over_ipv6_calls = 0;
 
   /* No valid addresses */
-  router_has_ipv6_orport_result = true;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = true;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(NULL, NULL), OP_EQ, NULL);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
-  router_has_ipv6_orport_result = false;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = false;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(NULL, NULL), OP_EQ, NULL);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
   /* One valid address: IPv4 */
-  router_has_ipv6_orport_result = true;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = true;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(&ipv4_ap, NULL), OP_EQ, &ipv4_ap);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
-  router_has_ipv6_orport_result = false;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = false;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(&ipv4_ap, NULL), OP_EQ, &ipv4_ap);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
   /* One valid address: IPv6 */
-  router_has_ipv6_orport_result = true;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = true;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(NULL, &ipv6_ap), OP_EQ, &ipv6_ap);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
-  router_has_ipv6_orport_result = false;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = false;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(NULL, &ipv6_ap), OP_EQ, NULL);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
   /* Two valid addresses */
   const tor_addr_port_t *chosen_addr = NULL;
 
-  router_has_ipv6_orport_result = true;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = true;
+  mock_router_can_extend_over_ipv6_calls = 0;
   chosen_addr = circuit_choose_ip_ap_for_extend(&ipv4_ap, &ipv6_ap);
   tt_assert(chosen_addr == &ipv4_ap || chosen_addr == &ipv6_ap);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
-  router_has_ipv6_orport_result = false;
-  mock_router_ipv6_orport_calls = 0;
+  can_extend_over_ipv6_result = false;
+  mock_router_can_extend_over_ipv6_calls = 0;
   tt_ptr_op(circuit_choose_ip_ap_for_extend(&ipv4_ap, &ipv6_ap),
             OP_EQ, &ipv4_ap);
-  tt_int_op(mock_router_ipv6_orport_calls, OP_EQ, 1);
+  tt_int_op(mock_router_can_extend_over_ipv6_calls, OP_EQ, 1);
 
  done:
   UNMOCK(get_options);
   or_options_free(fake_options);
   mocked_options = NULL;
 
-  UNMOCK(router_has_advertised_ipv6_orport);
+  UNMOCK(router_can_extend_over_ipv6);
 
   tor_free(fake_options);
 }
@@ -968,9 +968,9 @@ test_circuit_open_connection_for_extend(void *arg)
   mock_channel_connect_calls = 0;
   mock_channel_connect_nchan = NULL;
 
-  MOCK(router_has_advertised_ipv6_orport,
-       mock_router_has_advertised_ipv6_orport);
-  router_has_ipv6_orport_result = true;
+  MOCK(router_can_extend_over_ipv6,
+       mock_router_can_extend_over_ipv6);
+  can_extend_over_ipv6_result = true;
 
   setup_full_capture_of_logs(LOG_INFO);
 
@@ -1110,7 +1110,7 @@ test_circuit_open_connection_for_extend(void *arg)
   or_options_free(fake_options);
   mocked_options = NULL;
 
-  UNMOCK(router_has_advertised_ipv6_orport);
+  UNMOCK(router_can_extend_over_ipv6);
 
   tor_free(ec);
   tor_free(circ->n_hop);