diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5bf4d28..0f04769 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -3,6 +3,6 @@ test:
     script:
         - apk update
         - apk add python3 npm
-        - npm install --global mocha
+        - npm install --global typescript mocha
         - tools/build --include-tests
         - mocha heimdall-test.mocha.js