diff --git a/code/espurna/homeassistant.ino b/code/espurna/homeassistant.ino
index e80fe2db..ce164184 100644
--- a/code/espurna/homeassistant.ino
+++ b/code/espurna/homeassistant.ino
@@ -430,6 +430,19 @@ void _haConfigure() {
     const bool enabled = getSetting("haEnabled", HOMEASSISTANT_ENABLED).toInt() == 1;
     _ha_send_flag = (enabled != _ha_enabled);
     _ha_enabled = enabled;
+
+    // https://github.com/xoseperez/espurna/issues/1273
+    // https://gitter.im/tinkerman-cat/espurna?at=5df8ad4655d9392300268a8c
+    // TODO: ensure that this is called before _lightConfigure()
+    //       in case useCSS value is ever cached by the lights module
+    #if LIGHT_PROVIDER != LIGHT_PROVIDER_NONE
+        if (enabled) {
+            if (getSetting("useCSS", LIGHT_USE_CSS).toInt() == 1) {
+                setSetting("useCSS", 0);
+            }
+        }
+    #endif
+
     _haSend();
 }
 
diff --git a/code/html/index.html b/code/html/index.html
index 83909788..0bdcdc7b 100644
--- a/code/html/index.html
+++ b/code/html/index.html
@@ -536,7 +536,12 @@
                                     <div class="pure-u-1 pure-u-lg-1-4"><input type="checkbox" name="useCSS" tabindex="12" /></div>
                                     <div class="pure-u-0 pure-u-lg-1-2"></div>
                                     <div class="pure-u-0 pure-u-lg-1-4"></div>
-                                    <div class="pure-u-1 pure-u-lg-3-4 hint">Use CSS style to report colors to MQTT and REST API. <br />Red will be reported as "#FF0000" if ON, otherwise "255,0,0"</div>
+                                    <div class="pure-u-1 pure-u-lg-3-4 hint">
+                                        <div class="module module-ha">
+                                            <strong>WARNING! </strong>Incompatible with Home Assistant MQTT integration
+                                        </div>
+                                        Use CSS style to report colors to MQTT and REST API. <br />Red will be reported as "#FF0000" if ON, otherwise "255,0,0"
+                                    </div>
                                 </div>
 
                                 <div class="pure-g">
@@ -1270,9 +1275,6 @@
                                     <div class="pure-u-0 pure-u-lg-1-4"></div>
                                     <div class="pure-u-1 pure-u-lg-3-4 hint">
                                         Home Assistant auto-discovery feature. Enable and save to add the device to your HA console.
-                                        <!-- removeIf(!light) -->
-                                        When using a colour light you might want to disable CSS style so Home Assistant can parse the color.
-                                        <!-- endRemoveIf(!light) -->
                                     </div>
                                 </div>