diff --git a/src/adt/index.js b/src/adt/index.js
index 18d8f7cc..d2f5f56d 100644
--- a/src/adt/index.js
+++ b/src/adt/index.js
@@ -1,2 +1,2 @@
-export * from './DummyHeap' ;
-export * from './DummyHeapWithoutReferences' ;
+export * from './DummyHeap.js' ;
+export * from './DummyHeapWithoutReferences.js' ;
diff --git a/src/index.js b/src/index.js
index 4ca75612..a8e70e40 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,4 +1,4 @@
-export * from './adt' ;
-export * from './parts' ;
-export * from './test' ;
-export * from './tester' ;
+export * from './adt/index.js' ;
+export * from './parts/index.js' ;
+export * from './test.js' ;
+export * from './tester.js' ;
diff --git a/src/parts/decreasekey.js b/src/parts/decreasekey.js
index 1738f9c7..5e962248 100644
--- a/src/parts/decreasekey.js
+++ b/src/parts/decreasekey.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 import { shuffle } from '@randomized/random' ;
 
 export function _decreasekey ( _test, length, heapname, Heap, diffname, diff, n ) {
diff --git a/src/parts/delete.js b/src/parts/delete.js
index c5f937ed..5cad424b 100644
--- a/src/parts/delete.js
+++ b/src/parts/delete.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 import { shuffle } from '@randomized/random' ;
 
 export function _del ( _test, length, heapname, Heap, diffname, diff, n ) {
diff --git a/src/parts/head.js b/src/parts/head.js
index 92050c78..290290c7 100644
--- a/src/parts/head.js
+++ b/src/parts/head.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 
 export function _head ( _test, length, heapname, Heap, diffname, diff, n ) {
 
diff --git a/src/parts/headreference.js b/src/parts/headreference.js
index 25834aaa..632973fb 100644
--- a/src/parts/headreference.js
+++ b/src/parts/headreference.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 
 export function _headreference ( _test, length, heapname, Heap, diffname, diff, n ) {
 
diff --git a/src/parts/increasekey.js b/src/parts/increasekey.js
index 7058bdaf..e1cd47a6 100644
--- a/src/parts/increasekey.js
+++ b/src/parts/increasekey.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 import { shuffle } from '@randomized/random' ;
 
 export function _increasekey ( _test, length, heapname, Heap, diffname, diff, n ) {
diff --git a/src/parts/index.js b/src/parts/index.js
index 80412309..e489135f 100644
--- a/src/parts/index.js
+++ b/src/parts/index.js
@@ -1,10 +1,10 @@
-export * from './decreasekey' ;
-export * from './delete' ;
-export * from './head' ;
-export * from './headreference' ;
-export * from './increasekey' ;
-export * from './merge' ;
-export * from './popreference' ;
-export * from './pushpop' ;
-export * from './pushreference' ;
-export * from './update' ;
+export * from './decreasekey.js' ;
+export * from './delete.js' ;
+export * from './head.js' ;
+export * from './headreference.js' ;
+export * from './increasekey.js' ;
+export * from './merge.js' ;
+export * from './popreference.js' ;
+export * from './pushpop.js' ;
+export * from './pushreference.js' ;
+export * from './update.js' ;
diff --git a/src/parts/merge.js b/src/parts/merge.js
index 9f061341..5e845437 100644
--- a/src/parts/merge.js
+++ b/src/parts/merge.js
@@ -1,4 +1,4 @@
-import { tester2 } from '../tester' ;
+import { tester2 } from '../tester.js' ;
 
 export function _merge ( _test, length, heapname, Heap, diffname, diff, m, n ) {
 
diff --git a/src/parts/popreference.js b/src/parts/popreference.js
index 875bb43d..25d75e65 100644
--- a/src/parts/popreference.js
+++ b/src/parts/popreference.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 
 export function _popreference ( _test, length, heapname, Heap, diffname, diff, n ) {
 
diff --git a/src/parts/pushpop.js b/src/parts/pushpop.js
index 2d8860db..cf76a2e1 100644
--- a/src/parts/pushpop.js
+++ b/src/parts/pushpop.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 
 export function _pushpop ( _test, length, heapname, Heap, diffname, diff, n ) {
 
diff --git a/src/parts/pushreference.js b/src/parts/pushreference.js
index 8e49e22a..2ecebffb 100644
--- a/src/parts/pushreference.js
+++ b/src/parts/pushreference.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 import { shuffle } from '@randomized/random' ;
 
 export function _pushreference ( _test, length, heapname, Heap, diffname, diff, n ) {
diff --git a/src/parts/update.js b/src/parts/update.js
index 0ef487d2..ef9f7233 100644
--- a/src/parts/update.js
+++ b/src/parts/update.js
@@ -1,4 +1,4 @@
-import { tester } from '../tester' ;
+import { tester } from '../tester.js' ;
 import { shuffle } from '@randomized/random' ;
 
 export function _update ( _test, length, heapname, Heap, diffname, diff, n ) {
diff --git a/src/test.js b/src/test.js
index 0c0e3ead..fb84fd0d 100644
--- a/src/test.js
+++ b/src/test.js
@@ -10,7 +10,7 @@ import {
 	headreference ,
 	popreference ,
 	pushreference ,
-} from './parts' ;
+} from './parts/index.js' ;
 
 export function test ( _test , heaps , { references , length , lengths , lengths1 , lengths2 } = {
 	references : true ,
diff --git a/test/src/all.js b/test/src/all.js
index a720d7e5..36eb0529 100644
--- a/test/src/all.js
+++ b/test/src/all.js
@@ -3,7 +3,7 @@ import ava from 'ava' ;
 
 import { partial , create } from '@functional-abstraction/functools' ;
 
-import * as spec from '../../src' ;
+import * as spec from '../../src/index.js' ;
 
 spec.test(
 	ava ,