diff --git a/dash/dash-renderer/src/actions/callbacks.ts b/dash/dash-renderer/src/actions/callbacks.ts
index ee3a251378..37aab3f194 100644
--- a/dash/dash-renderer/src/actions/callbacks.ts
+++ b/dash/dash-renderer/src/actions/callbacks.ts
@@ -791,7 +791,7 @@ export function executeCallback(
         }
 
         const __execute = async (): Promise<CallbackResult> => {
-            const loadingOutputs = outputs.map(out => ({
+            const loadingOutputs = flatten(outputs).map(out => ({
                 path: getPath(paths, out.id),
                 property: out.property?.split('@')[0],
                 id: stringifyId(out.id)