diff --git a/setup.cfg b/setup.cfg
index ee9ffc9d..522dba9b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -62,7 +62,7 @@ install_requires =
 	cryptography
 	pynacl
 	ecdsa
-	aiohttp
+	aiohttp==3.12.9 # in later versions, TCPConnector.close() is a coroutine
 	requests
 	pexpect
 	lxml