1 files changed, 4 insertions, 0 deletions
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 8d5bde0..4250bb0 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -15,6 +15,7 @@ import contextvars
 import functools
 import inspect
 import itertools
+import math
 import types
 import warnings
 import weakref
@@ -646,6 +647,9 @@ async def sleep(delay, result=None):
         await __sleep0()
         return result
 
+    if math.isnan(delay):
+        raise ValueError("Invalid delay: NaN (not a number)")
+
     loop = events.get_running_loop()
     future = loop.create_future()
     h = loop.call_later(delay,