diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6d2a3974c..b28e171f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,2 +1,3 @@
 - Allow Functions to specify vpcConnector as a string parameter (#1329)
 - Upgrade jsonwebtoken to version 9 (#1336)
+- Adds 'eventarcpublishing' as required API to custom event function
diff --git a/src/v2/providers/eventarc.ts b/src/v2/providers/eventarc.ts
index 34c30d8ce..42270ffaf 100644
--- a/src/v2/providers/eventarc.ts
+++ b/src/v2/providers/eventarc.ts
@@ -225,5 +225,12 @@ export function onCustomEventPublished<T = any>(
 
   func.__endpoint = endpoint;
 
+  func.__requiredAPIs = [
+    {
+      api: "eventarcpublishing.googleapis.com",
+      reason: "Needed for custom event functions",
+    },
+  ];
+
   return func;
 }