diff --git a/src/findUnit.ts b/src/findUnit.ts
index 10fcc2e..c8455e9 100644
--- a/src/findUnit.ts
+++ b/src/findUnit.ts
@@ -1,4 +1,4 @@
-import units, { UnitKey } from './units'
+import units, { UnitKey } from './units/index.js'
 import siPrefixes from './SIPrefixes'
 
 const SQUARE_SYMBOLS = ['²', '2']
diff --git a/src/measure.ts b/src/measure.ts
index cc532db..e62f771 100644
--- a/src/measure.ts
+++ b/src/measure.ts
@@ -1,5 +1,5 @@
 import findUnit from './findUnit'
-import { UnitKey } from './units'
+import { UnitKey } from './units/index.js'
 
 /**
  * Measure of value with unit.
diff --git a/src/measureSelector.ts b/src/measureSelector.ts
index 85cdc28..8c7b17f 100644
--- a/src/measureSelector.ts
+++ b/src/measureSelector.ts
@@ -1,6 +1,6 @@
 import findUnit from './findUnit'
 import Measure from './measure'
-import { UnitKey } from './units'
+import { UnitKey } from './units/index.js'
 
 const toMeasure = (
   {