diff --git a/src/connections/destinations/catalog/actions-marketo-static-lists/index.md b/src/connections/destinations/catalog/actions-marketo-static-lists/index.md
index a8a959cea6..67dce21050 100644
--- a/src/connections/destinations/catalog/actions-marketo-static-lists/index.md
+++ b/src/connections/destinations/catalog/actions-marketo-static-lists/index.md
@@ -57,6 +57,9 @@ In this step, you'll create an API-Only Marketo user with both Access API and Le
 > warning "Warning:"
 > Do not create a list in the folder for the audience. Segment creates the list for you!
 
+### Using Marketo Static Lists (Actions) with the Event Tester
+This destination keeps track of a `List Id` field for you on the backend. That field is added to payloads as Segment processes them. This means that the Event Tester can't be used out-of-the-box as it can with most destinations. To test an event using the Event Tester for Marketo Static Lists (Actions), you need to add a valid `List Id` to the payload at the `context.personas.external_audience_id` key.
+
 ### Using Marketo Static Lists (Actions) destination with Engage
 
 1. From your Segment workspace, go to **Engage → Engage Settings → Destinations → Add Destination**, and then Search for Marketo Static Lists (Actions).