diff --git a/reference/configuration.html.markerb b/reference/configuration.html.markerb
index b15cced9bd..9339bbccce 100644
--- a/reference/configuration.html.markerb
+++ b/reference/configuration.html.markerb
@@ -409,7 +409,7 @@ You can use the same `machine_checks` section for HTTP services as for [`service
[http_services.machine_checks]
image = "curlimages/curl"
entrypoint = ["/bin/sh", "-c"]
- command = ["curl", "$FLY_TEST_MACHINE_IP", "|", "grep", "Hello, World!"]
+ command = ["curl http://[$FLY_TEST_MACHINE_IP] | grep 'Hello, World!'"]
kill_signal = "SIGKILL"
kill_timeout = "5s"
```
@@ -662,13 +662,13 @@ Times are in milliseconds unless units are specified.
### `services.machine_checks`
-Machine checks work a bit differently than the other checks. They run on each deploy, and if they fail, the deploy is stopped. A new Machine is spawned with the environment variable `FLY_TEST_MACHINE_IP` set to the IP address of the Machine being tested. This is useful for running integration tests on Machines before a deployment. Here's an example:
+Machine checks work a bit differently than the other checks. They run on each deploy, and if they fail, the deploy is stopped. A new Machine is spawned with the environment variable `FLY_TEST_MACHINE_IP` set to the [6PN IPv6 address](/docs/networking/private-networking/#6pn-addresses-in-detail) of the Machine being tested. This is useful for running integration tests on Machines before a deployment. Here's an example:
```toml
[[services.machine_checks]]
image = "curlimages/curl"
entrypoint = ["/bin/sh", "-c"]
- command = ["curl", "$FLY_TEST_MACHINE_IP", "|", "grep", "Hello, World!"]
+ command = ["curl http://[$FLY_TEST_MACHINE_IP] | grep 'Hello, World!'"]
kill_signal = "SIGKILL"
kill_timeout = "5s"
```