diff --git a/docs/configuration/indexes.md b/docs/configuration/indexes.md
index 373d7307e..a4e66ea6e 100644
--- a/docs/configuration/indexes.md
+++ b/docs/configuration/indexes.md
@@ -207,7 +207,9 @@ authenticate = "always"
 ```
 
 When `authenticate` is set to `always`, uv will eagerly search for credentials and error if
-credentials cannot be found.
+credentials cannot be found. If the discovered credentials are not valid (i.e., the index returns a
+HTTP 401 or 403), then uv will treat packages as unavailable and query the next configured index as
+described in the [index strategy](#searching-across-multiple-indexes) section.
 
 ### Disabling authentication