diff --git a/.travis.yml b/.travis.yml
index ee2f9be..f968a3a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,6 +10,7 @@ install:
   - pip install i3ipc
   - pip install psutil
   - pip install netifaces
+  - pip install yaml
   - pip install -U coverage==4.3
   - pip install codeclimate-test-reporter
 script: