diff --git a/src/cluster.jl b/src/cluster.jl
index 11ed823..a27638f 100644
--- a/src/cluster.jl
+++ b/src/cluster.jl
@@ -466,7 +466,7 @@ function addprocs(manager::ClusterManager; kwargs...)
     # Call worker-starting callbacks
     warning_interval = params[:callback_warning_interval]
     _run_callbacks_concurrently("worker-starting", worker_starting_callbacks,
-                                warning_interval, [(manager, kwargs)])
+                                warning_interval, [(manager, params)])
 
     # Add new workers
     new_workers = @lock worker_lock addprocs_locked(manager::ClusterManager, params)