diff --git a/docs/sources/datasources/alertmanager.md b/docs/sources/datasources/alertmanager.md
index 76ac065fff9..7ecf06977ca 100644
--- a/docs/sources/datasources/alertmanager.md
+++ b/docs/sources/datasources/alertmanager.md
@@ -26,6 +26,8 @@ datasources:
     type: alertmanager
     url: http://localhost:9090
     access: proxy
+    jsonData:
+      implementation: 'prometheus'
     # optionally
     basicAuth: true
     basicAuthUser: my_user