diff --git a/CHANGELOG.md b/CHANGELOG.md
index 015180e..b5e4352 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
    invalid, having a zeroed control message header. These are now properly
    populated
 
+3. `mctpd` will no longer (incorrectly) reject SetupEndpoint / AssignEndpoint
+   calls for endpoints that do not implement the optional Get Endpoint UUID
+   and Get Vendor Defined Message Support commands.
+
 ### Changed
 
 1. `mctpd`'s `mode` configuration (setting bus owner vs. endpoint roles) is
@@ -45,6 +49,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
    Set Endpoint ID commands before performing enumeration on the (bus-owner)
    peer.
 
+4. `mctpd` now requires remote endpoints to implement the Get Message Type
+   Support command, as it is mandatory according to DSP0236. Peers not
+   implementing this will not be published, as enumeration will fail.
+
 ## [2.5] - 2026-02-17
 
 ### Added
diff --git a/src/mctpd.c b/src/mctpd.c
index c9a41db..983471e 100644
--- a/src/mctpd.c
+++ b/src/mctpd.c
@@ -3425,9 +3425,10 @@ static int query_peer_properties(struct peer *peer)
 	int rc;
 
 	rc = query_get_peer_msgtypes(peer);
-	if (rc < 0 && peer->ctx->verbose) {
+	if (rc < 0) {
 		errno = -rc;
 		warn("Error getting endpoint types for %s", peer_tostr(peer));
+		return -1;
 	}
 
 	for (unsigned int i = 0; i < peer->num_message_types; i++) {
@@ -3454,7 +3455,7 @@ static int query_peer_properties(struct peer *peer)
 	}
 
 	// TODO: emit property changed? Though currently they are all const.
-	return rc;
+	return 0;
 }
 
 static int peer_neigh_update(struct peer *peer, uint16_t type)
@@ -3536,9 +3537,9 @@ static int setup_added_peer(struct peer *peer)
 
 	rc = publish_peer(peer);
 out:
-	if (rc < 0) {
+	if (rc < 0)
 		remove_peer(peer);
-	}
+
 	return rc;
 }
 
@@ -3975,9 +3976,13 @@ static int method_net_learn_endpoint(sd_bus_message *call, void *data,
 		goto err;
 	}
 
-	query_peer_properties(peer);
+	rc = query_peer_properties(peer);
+	if (rc)
+		goto err;
 
-	publish_peer(peer);
+	rc = publish_peer(peer);
+	if (rc)
+		goto err;
 
 	peer_path = path_from_peer(peer);
 	if (!peer_path)
diff --git a/tests/test_mctpd.py b/tests/test_mctpd.py
index 02e4239..7853794 100644
--- a/tests/test_mctpd.py
+++ b/tests/test_mctpd.py
@@ -157,6 +157,65 @@ async def test_setup_endpoint_conflict(dbus, mctpd):
     assert eid1 != eid2
 
 
+class CommandUnimplementedEndpoint(Endpoint):
+    """An endpoint where one command (specified via opcode) reports as
+    unimplemented.
+    """
+
+    def __init__(self, opcode, *args, **kwargs):
+        self.unimplemented_opcode = opcode
+        super().__init__(*args, **kwargs)
+
+    async def handle_mctp_control(self, sock, src_addr, msg):
+        flags, opcode = msg[0:2]
+        if opcode != self.unimplemented_opcode:
+            return await super().handle_mctp_control(sock, src_addr, msg)
+        # report not implemented
+        data = bytes([flags & 0x1F, opcode, 0x05])
+        dst_addr = MCTPSockAddr.for_ep_resp(self, src_addr, sock.addr_ext)
+        await sock.send(dst_addr, data)
+
+
+async def test_setup_endpoint_no_get_msg_types(dbus, mctpd):
+    """Test that endpoint enumeration fails if the endpoint does not
+    support the (mandatory) Get Message Type Support command.
+    """
+    iface = mctpd.system.interfaces[0]
+    ep = CommandUnimplementedEndpoint(0x05, iface, bytes([0x1E]))
+    mctpd.network.add_endpoint(ep)
+    mctp = await mctpd_mctp_iface_obj(dbus, iface)
+
+    with pytest.raises(asyncdbus.errors.DBusError):
+        await mctp.call_setup_endpoint(ep.lladdr)
+
+
+async def test_setup_endpoint_no_get_vdm_types(dbus, mctpd):
+    """Test that we can enumerate an endpoint where the (optional)
+    Get Vendor Defined Message Support command is not implemented
+    """
+    iface = mctpd.system.interfaces[0]
+    ep = CommandUnimplementedEndpoint(0x06, iface, bytes([0x1E]))
+    mctpd.network.add_endpoint(ep)
+    mctp = await mctpd_mctp_iface_obj(dbus, iface)
+
+    (eid, net, path, new) = await mctp.call_setup_endpoint(ep.lladdr)
+    assert eid == ep.eid
+
+
+async def test_setup_endpoint_no_get_uuid(dbus, mctpd):
+    """Test that we can enumerate an endpoint where the (optional)
+    Get Endpoint UUID command is not implemented
+    """
+
+    iface = mctpd.system.interfaces[0]
+    ep = CommandUnimplementedEndpoint(0x03, iface, bytes([0x1E]))
+    mctpd.network.add_endpoint(ep)
+    mctp = await mctpd_mctp_iface_obj(dbus, iface)
+
+    (eid, net, path, new) = await mctp.call_setup_endpoint(ep.lladdr)
+    assert eid == ep.eid
+
+
 async def test_remove_endpoint(dbus, mctpd):
     """Test neighbour removal"""
     iface = mctpd.system.interfaces[0]
@@ -1870,14 +1929,9 @@ async def handle_mctp_control(self, sock, addr, data):
     ep.lladdr = bytes([0x1C])  # change lladdr to force retry
     ep.timeout_count = 5  # timeout five times before responding
 
-    # call setup_endpoint again, which will trigger query of peer properties
-    (eid, net, path, new) = await mctp.call_setup_endpoint(ep.lladdr)
-
-    # timeout five times does prevent us from getting the correct message types
-    objep = await mctpd_mctp_endpoint_common_obj(dbus, path)
-    objtypes = list(await objep.get_supported_message_types())
-    expected_types = []  # exceeded retry limit, so no types known
-    assert objtypes == expected_types
+    # call setup_endpoint again, which will fail on the types query
+    with pytest.raises(asyncdbus.errors.DBusError):
+        await mctp.call_setup_endpoint(ep.lladdr)
 
     # exit mctpd
     res = await mctpd.stop_mctpd()