diff --git a/.travis.yml b/.travis.yml
index a8db9ac0a..d199d5076 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 before_install:
-    - sudo apt-get install ed lua5.2 ninja
+    - sudo apt-get install ed lua5.2 lua-posix ninja
 language: c
 script:
     - make PREFIX=/tmp/acki -j4