diff --git a/lib/paths-cache.js b/lib/paths-cache.js
index 717bc19..de401b1 100644
--- a/lib/paths-cache.js
+++ b/lib/paths-cache.js
@@ -147,6 +147,18 @@ export default class PathsCache extends EventEmitter {
     this._repositories = repositories.filter((r) => r !== null) // filter out non-repository directories
   }
 
+  /**
+   * Add watchers for all the projectDirectories
+   * @return {Promise<Array<Array<string>>}
+   * @private
+   */
+  async _addWatchers() {
+    const result = await Promise.all(
+      this._projectDirectories.map((projectDirectory) => this._addWatcherForDirectory(projectDirectory))
+    )
+    return result
+  }
+
   /**
    * Add a watcher for the projectDirectory
    * @param  {Directory} projectDirectory