diff --git a/tox.ini b/tox.ini
index 27d21ade2..ada211b3c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -77,7 +77,7 @@ deps =
     pyOpenSSL==16.2.0
     queuelib==1.4.2
     service_identity==16.0.0
-    Twisted==17.9.0
+    Twisted[http2]==17.9.0
     w3lib==1.17.0
     zope.interface==4.1.3
     -rtests/requirements-py3.txt