diff --git a/esphome/dashboard/dashboard.py b/esphome/dashboard/dashboard.py
index d0e9a82523..eb5dbd6b4a 100644
--- a/esphome/dashboard/dashboard.py
+++ b/esphome/dashboard/dashboard.py
@@ -523,8 +523,8 @@ class EsphomeUpdateAllHandler(EsphomeCommandWebSocket):
 
 class SerialPortRequestHandler(BaseHandler):
     @authenticated
-    def get(self):
-        ports = get_serial_ports()
+    async def get(self):
+        ports = await tornado.ioloop.IOLoop.run_in_executor(None, get_serial_ports)
         data = []
         for port in ports:
             desc = port.description