diff --git a/src/integrations/home-assistant/home-assistant.service.spec.ts b/src/integrations/home-assistant/home-assistant.service.spec.ts
index 8fbcfa87..78d2932b 100644
--- a/src/integrations/home-assistant/home-assistant.service.spec.ts
+++ b/src/integrations/home-assistant/home-assistant.service.spec.ts
@@ -558,6 +558,19 @@ describe('HomeAssistantService', () => {
       }
     );
 
+    it('should clear old retained status messages from pre-2.18.x', async () => {
+      await service.onModuleInit();
+      service.handleNewEntity(new Sensor('test', 'Test'));
+
+      expect(mockMqttClient.publish).toHaveBeenCalledWith(
+        'room-assistant/sensor/test-instance-test/status',
+        '',
+        {
+          retain: true,
+        }
+      );
+    });
+
     it('should send an instance status message as heartbeat', async () => {
       await service.onModuleInit();
       mockMqttClient.publish.mockClear();
diff --git a/src/integrations/home-assistant/home-assistant.service.ts b/src/integrations/home-assistant/home-assistant.service.ts
index 7baec07e..ebbeaa8a 100644
--- a/src/integrations/home-assistant/home-assistant.service.ts
+++ b/src/integrations/home-assistant/home-assistant.service.ts
@@ -171,7 +171,11 @@ export class HomeAssistantService
     this.entityConfigs.set(combinedId, config);
 
     this.sendDiscoveryMessage(config);
-    this.sendEntityStatus(config);
+
+    if (config.availability.length > 0) {
+      this.clearRetained(config.availability[0].topic); // for upgrades from < 2.18.x
+      this.sendEntityStatus(config);
+    }
   }
 
   /**
@@ -434,6 +438,15 @@ export class HomeAssistantService
     });
   }
 
+  /**
+   * Clear any retained message from the given MQTT topic.
+   *
+   * @param topic - Topic to clear ("delete")
+   */
+  private async clearRetained(topic: string): Promise<void> {
+    await this.mqttClient.publish(topic, '', { retain: true });
+  }
+
   /**
    * Publish entity status to its availability topic with MQTT.
    *