diff --git a/types/read-pkg-up/read-pkg-up-tests.ts b/types/read-pkg-up/read-pkg-up-tests.ts
index e01dd4e123..f536f275d2 100644
--- a/types/read-pkg-up/read-pkg-up-tests.ts
+++ b/types/read-pkg-up/read-pkg-up-tests.ts
@@ -1,4 +1,6 @@
 import ReadPkgUp = require('read-pkg-up');
 
+ReadPkgUp().then(pkg => typeof pkg === 'object');
 ReadPkgUp({cwd: '.', normalize: false}).then(pkg => typeof pkg === 'object');
+typeof ReadPkgUp.sync() === 'object';
 typeof ReadPkgUp.sync({cwd: '.', normalize: false}) === 'object';