diff --git a/understanding-asynchronous-programming/example_6.py b/understanding-asynchronous-programming/example_6.py
index 1f4e3d2810..792decee4d 100644
--- a/understanding-asynchronous-programming/example_6.py
+++ b/understanding-asynchronous-programming/example_6.py
@@ -6,7 +6,8 @@
 
 async def task(name, work_queue):
     timer = Timer(text=f"Task {name} elapsed time: {{:.1f}}")
-    async with aiohttp.ClientSession() as session:
+    # default max_field_size=8190 is too low for Twitter's content-security-policy Header
+    async with aiohttp.ClientSession(max_field_size=16380) as session:
         while not work_queue.empty():
             url = await work_queue.get()
             print(f"Task {name} getting URL: {url}")