diff --git a/.circleci/config.yml b/.circleci/config.yml
index 925d765..5d162e9 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -100,6 +100,9 @@ jobs:
           path: ~/offen
       - restore_cache:
           key: offen-script-{{ checksum "package.json" }}
+      - run:
+          name: Install lsof
+          command: sudo apt-get install lsof
       - run:
           name: Install dependencies
           command: npm install
@@ -140,6 +143,9 @@ jobs:
           path: ~/offen
       - restore_cache:
           key: offen-packages-{{ checksum "package.json" }}
+      - run:
+          name: Install lsof
+          command: sudo apt-get install lsof
       - run:
           name: Install dependencies
           command: npm install