diff --git a/.travis.yml b/.travis.yml
index f3c1432..de31b99 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,3 +8,4 @@ addons:
       - libmagic-mgc
 script:
   - ./test.sh
+  - file -b --mime-type tests/data/streams.json