diff --git a/tools/requirements.txt b/tools/requirements.txt
index 920343fad..f4421312d 100644
--- a/tools/requirements.txt
+++ b/tools/requirements.txt
@@ -3,5 +3,5 @@ structlog
 taskcluster
 raven
 
-# Limit yarl version to avoid using the alpha 1.4.0a that breaks builds
-yarl==1.3.0
+# limit async-timeout version to avoid using the alpha 4.0.0a0
+async-timeout<4.0,>=3.0