diff --git a/.travis.yml b/.travis.yml
index 1119b740..0b8405af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,8 @@ install:
 # CryFS needs cmake >= 3.3, install it.
 - wget --no-check-certificate https://cmake.org/files/v3.3/cmake-3.3.2-Linux-x86_64.tar.gz
   && tar -xf cmake-3.3.2-Linux-x86_64.tar.gz
-  && cp -R cmake-3.3.2-Linux-x86_64/* /usr
+  && sudo cp -R cmake-3.3.2-Linux-x86_64/* /usr
+  && rm -r cmake-3.3.2-Linux-x64_64 cmake-3.3.2-Linux-x86_64.tar.gz
 - cmake --version
 #  Use /dev/urandom when /dev/random is accessed, because travis doesn't have enough entropy
 - sudo cp -a /dev/urandom /dev/random