diff --git a/README.md b/README.md
index 02a4ba2..ba3b976 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,11 @@ and permissions on Google Cloud.
 -   For authenticating via Workload Identity Federation, you must create and
     configure a Google Cloud Workload Identity Provider. See [setup](#setup)
     for instructions.
+    
+## Limitations
+
+-   This Action does not support authenticating through service accounts via
+    Domain-Wide Delegation.
 
 
 ## Usage