diff --git a/.Rbuildignore b/.Rbuildignore
index 5219fdf..c7d1c3e 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -1,3 +1,5 @@
 ^.*\.Rproj$
 ^.*\.Rproj\.user$
 ^\.Rproj\.user$
+^images$
+^\.travis\.yml$
diff --git a/.travis.yml b/.travis.yml
index 4f65ce0..2d9e173 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,13 +1,5 @@
-language: r
-sudo: true
+# R for travis: see documentation at https://docs.travis-ci.com/user/languages/r
+
+language: R
 cache: packages
 pandoc_version: 2.3.1
-dist: trusty
-
-before_install:
-  - sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable --yes
-  - sudo apt-get --yes --force-yes update -qq
-  - sudo apt-get install -y libudunits2-dev libproj-dev libgeos++-dev libgdal-dev libv8-dev
-
-compiler:
-  - clang