diff --git a/.travis.yml b/.travis.yml
index 1681b81..28b7594 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,7 @@ env:
         secure: "BB9eiRNXC1PfNRLEifc0yQQZnM25zqaWNGVWN+atzT+NkxhVKyVr8+DoyPYaa8tOKybuSZhVkKnIiCd8iGMe3v+WyuHKFuhdiwdnEQhxbBlUCb9dDLEexI+J8QiYwC8AW/t6H9LWVwSka0RI3GJujJ8HKIBzW45I/j+1NlUte8U="
 before_script:
     - sudo apt-get install -qq libgmp-dev libmpfr-dev doxygen graphviz
-    - apt-get remove doxygen
+    - sudo apt-get remove doxygen
     - wget http://www.flintlib.org/flint-2.4.3.tar.gz
     - tar -xzf flint-2.4.3.tar.gz
     - cd flint-2.4.3