diff --git a/.travis.yml b/.travis.yml
index e482b50..0249f8e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -50,7 +50,7 @@ matrix:
       rust: nightly
       os: linux
       script:
-        - cargo doc --features docs unstable
+        - cargo doc --features docs,unstable
 
     - name: book
       rust: nightly