diff --git a/packages/kbn-pm/dist/index.js b/packages/kbn-pm/dist/index.js
index 93c0e111f0d38..56a18caef6407 100644
--- a/packages/kbn-pm/dist/index.js
+++ b/packages/kbn-pm/dist/index.js
@@ -11064,7 +11064,8 @@ let run = exports.run = (() => {
                 e: 'exclude',
                 h: 'help',
                 i: 'include'
-            }
+            },
+            boolean: ['prefer-offline', 'frozen-lockfile']
         });
         const args = options._;
         if (options.help || args.length === 0) {
@@ -12199,8 +12200,7 @@ const BootstrapCommand = exports.BootstrapCommand = {
                 batchByWorkspace: true
             });
             const batchedProjects = (0, _projects.topologicallyBatchProjects)(projects, projectGraph);
-            const frozenLockfile = options['frozen-lockfile'] === true;
-            const extraArgs = frozenLockfile ? ['--frozen-lockfile'] : [];
+            const extraArgs = [...(options['frozen-lockfile'] === true ? ['--frozen-lockfile'] : []), ...(options['prefer-offline'] === true ? ['--prefer-offline'] : [])];
             _log.log.write(_chalk2.default.bold('\nRunning installs in topological order:'));
             for (const batch of batchedProjectsByWorkspace) {
                 for (const project of batch) {
diff --git a/packages/kbn-pm/src/cli.ts b/packages/kbn-pm/src/cli.ts
index 07383f89b8165..d7e3aafd13fce 100644
--- a/packages/kbn-pm/src/cli.ts
+++ b/packages/kbn-pm/src/cli.ts
@@ -65,6 +65,7 @@ export async function run(argv: string[]) {
       h: 'help',
       i: 'include',
     },
+    boolean: ['prefer-offline', 'frozen-lockfile'],
   });
 
   const args = options._;
diff --git a/packages/kbn-pm/src/commands/bootstrap.ts b/packages/kbn-pm/src/commands/bootstrap.ts
index 2469e4cca1cb1..be4b9da7bf516 100644
--- a/packages/kbn-pm/src/commands/bootstrap.ts
+++ b/packages/kbn-pm/src/commands/bootstrap.ts
@@ -35,8 +35,10 @@ export const BootstrapCommand: ICommand = {
     });
     const batchedProjects = topologicallyBatchProjects(projects, projectGraph);
 
-    const frozenLockfile = options['frozen-lockfile'] === true;
-    const extraArgs = frozenLockfile ? ['--frozen-lockfile'] : [];
+    const extraArgs = [
+      ...(options['frozen-lockfile'] === true ? ['--frozen-lockfile'] : []),
+      ...(options['prefer-offline'] === true ? ['--prefer-offline'] : []),
+    ];
 
     log.write(chalk.bold('\nRunning installs in topological order:'));
 
diff --git a/src/dev/ci_setup/setup.sh b/src/dev/ci_setup/setup.sh
index 5a8738018b681..71f8b10513e5e 100755
--- a/src/dev/ci_setup/setup.sh
+++ b/src/dev/ci_setup/setup.sh
@@ -84,6 +84,11 @@ hash -r
 yarnVersion="$(node -e "console.log(String(require('./package.json').engines.yarn || '').replace(/^[^\d]+/,''))")"
 npm install -g yarn@^${yarnVersion}
 
+###
+### setup yarn offline cache
+###
+yarn config set yarn-offline-mirror "$cacheDir/yarn-offline-cache"
+
 ###
 ### "install" yarn into this shell
 ###
@@ -95,7 +100,7 @@ hash -r
 ### install dependencies
 ###
 echo " -- installing node.js dependencies"
-yarn kbn bootstrap
+yarn kbn bootstrap --prefer-offline
 
 ###
 ### verify no git modifications