diff --git a/docs/credential_plugins.md b/docs/credential_plugins.md
index 6910c1942c..01f57a235c 100644
--- a/docs/credential_plugins.md
+++ b/docs/credential_plugins.md
@@ -33,12 +33,11 @@ the Machine Credential.
     system by specifying the source (in this example, the HashiCorp credential)
     and metadata about the path (e.g., `/some/path/to/my/password/`).
 
-Note that you can perform these lookups on *any* credential field - not just
-the `password` field for Machine credentials.  You could just as easily create
-an AWS credential and use lookups to retrieve the Access Key and Secret Key
-from an external secret management system.  Also note that external credential
-sources cannot ever be used to look up secrets for other external credential
-sources.
+Note that you can perform these lookups on *any* field for any non-external
+credential, including those with custom credential types. You could just as
+easily create an AWS credential and use lookups to retrieve the Access Key and
+Secret Key from an external secret management system. External credentials
+cannot have lookups applied to their fields.
 
 Writing Custom Credential Plugins
 ---------------------------------