diff --git a/package.json b/package.json
index 22095bb..0ec7a4d 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
   "dependencies": {
     "glob": "7.1.2",
     "minimist": "1.2.0",
+    "tslib": "1.9.0",
     "typescript": "2.8.3"
   },
   "scripts": {
diff --git a/yarn.lock b/yarn.lock
index b4496c7..39eaf5c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1972,7 +1972,7 @@ trim-off-newlines@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/trim-off-newlines/-/trim-off-newlines-1.0.1.tgz#9f9ba9d9efa8764c387698bcbfeb2c848f11adb3"
 
-tslib@^1.0.0, tslib@^1.8.0, tslib@^1.8.1:
+tslib@1.9.0, tslib@^1.0.0, tslib@^1.8.0, tslib@^1.8.1:
   version "1.9.0"
   resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.9.0.tgz#e37a86fda8cbbaf23a057f473c9f4dc64e5fc2e8"