diff --git a/values.yaml b/values.yaml
index 6492019..8d4209c 100644
--- a/values.yaml
+++ b/values.yaml
@@ -434,7 +434,7 @@ mastodon:
         enabled: false
         port: 9102
 
-    # Settings for Prometheus metrics.
+    # Settings for Prometheus metrics. NOTE: Only available in Mastodon v4.4.
     # For more information, see:
     # https://docs.joinmastodon.org/admin/config/#prometheus
     prometheus: