diff --git a/requirements.txt b/requirements.txt
index 37d328b3..7f7dc1ac 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
-aiohttp>=3.5.4
+aiohttp>=3.5.4,<4.0.0
 Babel>=2.6.0
 certifi>=2019.3.9