diff --git a/src/index.ts b/src/index.ts
index b3e76b4..c8cd4c7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,4 @@
 import Measure from './measure'
 export { default as measureFrom } from './measureSelector'
+export { UnitKey } from './units/index'
 export default Measure