diff --git a/.travis.yml b/.travis.yml
index e0807f5..11028dc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ install:
 addons:
   apt:
     packages:
+    - libgnutls28-dev
     - imagemagick
 script:
 - python check.py