diff --git a/.travis.yml b/.travis.yml
index ffc7b6a..1a283e5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1 +1,6 @@
+sudo: true
 language: crystal
+install:
+  - ./travis-install-lib-sodium.sh
+before_script:
+  - export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
diff --git a/travis-install-lib-sodium.sh b/travis-install-lib-sodium.sh
new file mode 100755
index 0000000..36541a7
--- /dev/null
+++ b/travis-install-lib-sodium.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+# The purpose of this file is to install libsodium in
+# the Travis CI environment. Outside this environment,
+# you would probably not want to install it like this.
+#
+# from: google/hat-backup
+
+set -e
+
+wget https://download.libsodium.org/libsodium/releases/libsodium-stable-2018-02-14.tar.gz
+tar xvfz libsodium-stable-2018-02-14.tar.gz
+cd libsodium-stable
+sudo ./configure
+sudo make
+sudo make install