diff --git a/.travis.yml b/.travis.yml
index a15e3b214ae3a91c3fba9cee23a8eb5ae22d9b06..ef85597e7f20e0d389bdf1f83f14d5d02f9f38c6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,7 +15,9 @@ addons:
       - libgsl-dev # dependency for gsl>copula>zinbwave
 
 install: skip
-
+before_install:
+  r_binary_packages:
+    - knitr
 #install:
 #  - R -e 'install.packages("devtools")'
 #  - R -e 'devtools::install(dependencies = TRUE, upgrade_dependencies = TRUE)'