diff --git a/.travis.yml b/.travis.yml
index d6147e3c..9ddbffd2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,7 @@ dist: xenial
 language: python
 
 python:
-  - "3.7"
+  - "3.6"
 
 cache:
   - pip
diff --git a/dev_requirements.txt b/dev_requirements.txt
index 63c51ccf..d185829a 100644
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -1,3 +1,5 @@
+asgiref
+attrs==19.3.0
 coveralls>=1.6.0
 channels>=2.0
 channels-redis