diff --git a/.travis.yml b/.travis.yml
index c65096a55..84aaec9cb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,4 @@
-dist: trusty
+dist: bionic
 language: generic
 install:
     - sudo apt-get update
@@ -10,3 +10,6 @@ before_script:
 script:
     - env LJHOME=$TRAVIS_BUILD_DIR perl -Iextlib/lib/perl5 t/00-compile.t
     - env LJHOME=$TRAVIS_BUILD_DIR perl -Iextlib/lib/perl5 t/02-tidy.t
+cache:
+    directories:
+        - extlib