diff --git a/.travis.yml b/.travis.yml
index de1ae31..3c42040 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,8 +3,11 @@ python:
   - "3.3"
   - "3.4"
   - "3.5"
-  - "3.5-dev" # 3.5 development branch
-  - "nightly" # currently points to 3.6-dev
+  - "3.6"
+  - "3.7-dev"
+  - "3.8-dev"
+  - "pypy3.5"
+cache: pip
 install: "pip install -r requirements.txt"
 script: nosetests dnstraceroute.py