diff --git a/docs/run-an-instance.md b/docs/run-an-instance.md
index 775f7f6..801895d 100644
--- a/docs/run-an-instance.md
+++ b/docs/run-an-instance.md
@@ -18,7 +18,7 @@ if you need help with installing docker, follow *only the first step* of these t
     ```  
     i'm using `nano` in this example, it may not be available in your distro. you can use any other text editor.  
 
-3. copy and paste the [sample config from here](https://github.com/wukko/cobalt/blob/current/docs/examples/docker-compose.example.json) for either web or api instance (or both, if you wish) and edit it to your needs.  
+3. copy and paste the [sample config from here](https://github.com/wukko/cobalt/blob/current/docs/examples/docker-compose.example.yml) for either web or api instance (or both, if you wish) and edit it to your needs.  
     make sure to replace default URLs with your own or cobalt won't work correctly.  
 
 4. finally, start the cobalt container (from cobalt directory):