diff --git a/infra/config/global/cr-buildbucket.cfg b/infra/config/global/cr-buildbucket.cfg
index 13455e5..34a9c1a 100644
--- a/infra/config/global/cr-buildbucket.cfg
+++ b/infra/config/global/cr-buildbucket.cfg
@@ -72,7 +72,7 @@
 }
 builder_mixins {
   name: "linux",
-  dimensions: "os:Ubuntu-16.04"
+  dimensions: "os:Ubuntu-18.04"
   recipe {
     properties_j: <<EOF
       $build/goma: {
@@ -262,7 +262,7 @@
 
     builders {
       name: "presubmit"
-      dimensions: "os:Ubuntu-16.04"
+      dimensions: "os:Ubuntu-18.04"
       recipe {
         name: "run_presubmit"
         properties: "repo_name:dawn"