diff --git a/nanshe_ipython.ipynb b/nanshe_ipython.ipynb
index 3265ba0..d744ff6 100644
--- a/nanshe_ipython.ipynb
+++ b/nanshe_ipython.ipynb
@@ -78,9 +78,10 @@
       "metadata": {},
       "outputs": [],
       "source": [
-        "from nanshe_workflow.par import set_num_workers, startup_distributed\n",
+        "from psutil import cpu_count\n",
+        "from nanshe_workflow.par import startup_distributed\n",
         "\n",
-        "num_workers = set_num_workers(num_workers)\n",
+        "num_workers = (num_workers or cpu_count())\n",
         "\n",
         "client = startup_distributed(num_workers)\n",
         "\n",