diff --git a/homeassistant/components/mqtt/cover.py b/homeassistant/components/mqtt/cover.py
index fd3e36c04e1..d920d12662f 100644
--- a/homeassistant/components/mqtt/cover.py
+++ b/homeassistant/components/mqtt/cover.py
@@ -245,11 +245,45 @@ class MqttCover(MqttEntity, CoverEntity):
         return PLATFORM_SCHEMA
 
     def _setup_from_config(self, config):
-        self._optimistic = config[CONF_OPTIMISTIC] or (
-            config.get(CONF_STATE_TOPIC) is None
+        no_position = (
+            config.get(CONF_SET_POSITION_TOPIC) is None
             and config.get(CONF_GET_POSITION_TOPIC) is None
         )
-        self._tilt_optimistic = config[CONF_TILT_STATE_OPTIMISTIC]
+        no_state = (
+            config.get(CONF_COMMAND_TOPIC) is None
+            and config.get(CONF_STATE_TOPIC) is None
+        )
+        no_tilt = (
+            config.get(CONF_TILT_COMMAND_TOPIC) is None
+            and config.get(CONF_TILT_STATUS_TOPIC) is None
+        )
+        optimistic_position = (
+            config.get(CONF_SET_POSITION_TOPIC) is not None
+            and config.get(CONF_GET_POSITION_TOPIC) is None
+        )
+        optimistic_state = (
+            config.get(CONF_COMMAND_TOPIC) is not None
+            and config.get(CONF_STATE_TOPIC) is None
+        )
+        optimistic_tilt = (
+            config.get(CONF_TILT_COMMAND_TOPIC) is not None
+            and config.get(CONF_TILT_STATUS_TOPIC) is None
+        )
+
+        if config[CONF_OPTIMISTIC] or (
+            (no_position or optimistic_position)
+            and (no_state or optimistic_state)
+            and (no_tilt or optimistic_tilt)
+        ):
+            # Force into optimistic mode.
+            self._optimistic = True
+
+        if (
+            config[CONF_TILT_STATE_OPTIMISTIC]
+            or config.get(CONF_TILT_STATUS_TOPIC) is None
+        ):
+            # Force into optimistic tilt mode.
+            self._tilt_optimistic = True
 
         value_template = self._config.get(CONF_VALUE_TEMPLATE)
         if value_template is not None:
@@ -418,17 +452,7 @@ class MqttCover(MqttEntity, CoverEntity):
                 "qos": self._config[CONF_QOS],
             }
 
-        if (
-            self._config.get(CONF_GET_POSITION_TOPIC) is None
-            and self._config.get(CONF_STATE_TOPIC) is None
-        ):
-            # Force into optimistic mode.
-            self._optimistic = True
-
-        if self._config.get(CONF_TILT_STATUS_TOPIC) is None:
-            # Force into optimistic tilt mode.
-            self._tilt_optimistic = True
-        else:
+        if self._config.get(CONF_TILT_STATUS_TOPIC) is not None:
             self._tilt_value = STATE_UNKNOWN
             topics["tilt_status_topic"] = {
                 "topic": self._config.get(CONF_TILT_STATUS_TOPIC),
diff --git a/tests/components/mqtt/test_cover.py b/tests/components/mqtt/test_cover.py
index 7d763895428..0ee2557fbd6 100644
--- a/tests/components/mqtt/test_cover.py
+++ b/tests/components/mqtt/test_cover.py
@@ -393,6 +393,34 @@ async def test_position_via_template_and_entity_id(hass, mqtt_mock):
     assert current_cover_position == 20
 
 
+@pytest.mark.parametrize(
+    "config, assumed_state",
+    [
+        ({"command_topic": "abc"}, True),
+        ({"command_topic": "abc", "state_topic": "abc"}, False),
+        # ({"set_position_topic": "abc"}, True), - not a valid configuration
+        ({"set_position_topic": "abc", "position_topic": "abc"}, False),
+        ({"tilt_command_topic": "abc"}, True),
+        ({"tilt_command_topic": "abc", "tilt_status_topic": "abc"}, False),
+    ],
+)
+async def test_optimistic_flag(hass, mqtt_mock, config, assumed_state):
+    """Test assumed_state is set correctly."""
+    assert await async_setup_component(
+        hass,
+        cover.DOMAIN,
+        {cover.DOMAIN: {**config, "platform": "mqtt", "name": "test", "qos": 0}},
+    )
+    await hass.async_block_till_done()
+
+    state = hass.states.get("cover.test")
+    assert state.state == STATE_UNKNOWN
+    if assumed_state:
+        assert ATTR_ASSUMED_STATE in state.attributes
+    else:
+        assert ATTR_ASSUMED_STATE not in state.attributes
+
+
 async def test_optimistic_state_change(hass, mqtt_mock):
     """Test changing state optimistically."""
     assert await async_setup_component(