diff --git a/.travis.yml b/.travis.yml
index 48913ddfb..086794f9e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,7 @@
 language: c
 
+dist: bionic
+
 # https://docs.travis-ci.com/user/caching/
 cache:
   directories:
@@ -29,6 +31,7 @@ matrix:
         # (also used to get a different cache key than the amd64 one)
       before_install:
         - export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/usr/local/lib"
+        - sudo apt-get -q update
         - sudo apt-get install -y libpcre3-dev
     - os: osx
       env:
diff --git a/vendor/nimbus-build-system b/vendor/nimbus-build-system
index 733e719a5..15f531200 160000
--- a/vendor/nimbus-build-system
+++ b/vendor/nimbus-build-system
@@ -1 +1 @@
-Subproject commit 733e719a589a9bfcb576046923c5334af1825d77
+Subproject commit 15f531200e5cacb266d30bff76e72e55c0ec5d24