diff --git a/pkg/services/ngalert/api/authorization.go b/pkg/services/ngalert/api/authorization.go
index b28080b8ac3..f753890cdf1 100644
--- a/pkg/services/ngalert/api/authorization.go
+++ b/pkg/services/ngalert/api/authorization.go
@@ -167,7 +167,7 @@ func (api *API) authorize(method, path string) web.Handler {
 	case http.MethodGet + "/api/alertmanager/{DatasourceUID}/config/api/v1/alerts":
 		eval = ac.EvalPermission(ac.ActionAlertingNotificationsExternalRead, datasources.ScopeProvider.GetResourceScopeUID(ac.Parameter(":DatasourceUID")))
 	case http.MethodPost + "/api/alertmanager/{DatasourceUID}/config/api/v1/alerts":
-		eval = ac.EvalPermission(ac.ActionAlertingNotificationsExternalWrite, datasources.ScopeProvider.GetResourceScope(ac.Parameter(":DatasourceID")))
+		eval = ac.EvalPermission(ac.ActionAlertingNotificationsExternalWrite, datasources.ScopeProvider.GetResourceScopeUID(ac.Parameter(":DatasourceUID")))
 	case http.MethodPost + "/api/alertmanager/{DatasourceUID}/config/api/v1/receivers/test":
 		eval = ac.EvalPermission(ac.ActionAlertingNotificationsExternalRead, datasources.ScopeProvider.GetResourceScopeUID(ac.Parameter(":DatasourceUID")))