diff --git a/src/lib/data/index.js b/src/lib/data/index.js
index c2c6f18..482b97d 100644
--- a/src/lib/data/index.js
+++ b/src/lib/data/index.js
@@ -6,9 +6,9 @@
  * Licensed under the LGPL2 license.
  */
 
-import option from './option';
-import atry from './try';
-import unit from './unit';
+import option from './option.js';
+import atry from './try.js';
+import unit from './unit.js';
 
 export default {
     option,
diff --git a/src/lib/genlex/genlex.js b/src/lib/genlex/genlex.js
index 2081294..c299dc6 100644
--- a/src/lib/genlex/genlex.js
+++ b/src/lib/genlex/genlex.js
@@ -1,7 +1,7 @@
-import response from "../parsec/response";
-import {F, C, N} from "../parsec";
-import unit from "../data/unit";
-import option from "../data/option";
+import response from "../parsec/response.js";
+import {F, C, N} from "../parsec/index.js";
+import unit from "../data/unit.js";
+import option from "../data/option.js";
 
 
 export class TokenDefinition {
diff --git a/src/lib/index.js b/src/lib/index.js
index 90d8335..60d0821 100644
--- a/src/lib/index.js
+++ b/src/lib/index.js
@@ -6,16 +6,16 @@
  * Licensed under the LGPL2 license.
  */
 
-import data from './data/index';
-import {GenLex,getMathGenLex} from './genlex/genlex';
-import parsec from './parsec/index';
-import Parser from './parsec/parser';
-import {F, C, N} from './parsec/index';
-import standard from './standard/index';
-import Streams from './stream/index';
+import data from './data/index.js';
+import {GenLex,getMathGenLex} from './genlex/genlex.js';
+import parsec from './parsec/index.js';
+import Parser from './parsec/parser.js';
+import {F, C, N} from './parsec/index.js';
+import standard from './standard/index.js';
+import Streams from './stream/index.js';
 
-import {accept, reject} from "./parsec/response";
-import {Tuple, isTuple, NEUTRAL, tuple} from "./data/tuple";
+import {accept, reject} from "./parsec/response.js";
+import {Tuple, isTuple, NEUTRAL, tuple} from "./data/tuple.js";
 
 
 const JSON = standard.jsonParser;
diff --git a/src/lib/parsec/chars-bundle.js b/src/lib/parsec/chars-bundle.js
index 990685b..e0374f0 100644
--- a/src/lib/parsec/chars-bundle.js
+++ b/src/lib/parsec/chars-bundle.js
@@ -5,8 +5,8 @@
  * Copyright (c) 2016 Didier Plaindoux
  * Licensed under the LGPL2 license.
  */
-import F from './flow-bundle';
-import {string} from './flow-bundle';
+import F from './flow-bundle.js';
+import {string} from './flow-bundle.js';
 
 const ASCII_LETTER = Symbol('ASCII');
 const OCCIDENTAL_LETTER = Symbol('OCCIDENTAL');
diff --git a/src/lib/parsec/flow-bundle.js b/src/lib/parsec/flow-bundle.js
index 81ebe80..37a720a 100644
--- a/src/lib/parsec/flow-bundle.js
+++ b/src/lib/parsec/flow-bundle.js
@@ -6,9 +6,9 @@
  * Licensed under the LGPL2 license.
  */
 
-import Parser, {eos} from './parser';
-import response from './response';
-import {NEUTRAL, Tuple} from "../data/tuple";
+import Parser, {eos} from './parser.js';
+import response from './response.js';
+import {NEUTRAL, Tuple} from "../data/tuple.js";
 
 // (Stream 'c -> number -> Response 'a 'c) -> Parser 'a 'c
 function parse(p) {
diff --git a/src/lib/parsec/index.js b/src/lib/parsec/index.js
index 9ddcd23..c0faa25 100644
--- a/src/lib/parsec/index.js
+++ b/src/lib/parsec/index.js
@@ -6,11 +6,11 @@
  * Licensed under the LGPL2 license.
  */
 
-import parser from './parser';
-import response from './response';
-import flow from './flow-bundle';
-import chars from './chars-bundle';
-import numbers from './numbers-bundle';
+import parser from './parser.js';
+import response from './response.js';
+import flow from './flow-bundle.js';
+import chars from './chars-bundle.js';
+import numbers from './numbers-bundle.js';
 
 export const C = chars;
 export const F = flow;
diff --git a/src/lib/parsec/numbers-bundle.js b/src/lib/parsec/numbers-bundle.js
index de5d272..ceac44e 100644
--- a/src/lib/parsec/numbers-bundle.js
+++ b/src/lib/parsec/numbers-bundle.js
@@ -6,8 +6,8 @@
  * Licensed under the LGPL2 license.
  */
 
-import C from './chars-bundle';
-import F from './flow-bundle';
+import C from './chars-bundle.js';
+import F from './flow-bundle.js';
 
 // unit -> Parser number char
 function number() {
diff --git a/src/lib/parsec/parser.js b/src/lib/parsec/parser.js
index 6e2f302..85e3a9a 100644
--- a/src/lib/parsec/parser.js
+++ b/src/lib/parsec/parser.js
@@ -12,14 +12,14 @@
  * http://research.microsoft.com/en-us/um/people/daan/download/papers/parsec-paper.pdf
  */
 
-import stream from '../stream/index';
+import stream from '../stream/index.js';
 
-import option from '../data/option';
+import option from '../data/option.js';
 
 
-import response from './response';
-import unit from "../data/unit";
-import {NEUTRAL, Tuple, isTuple} from "../data/tuple";
+import response from './response.js';
+import unit from "../data/unit.js";
+import {NEUTRAL, Tuple, isTuple} from "../data/tuple.js";
 
 
 /**
diff --git a/src/lib/standard/index.js b/src/lib/standard/index.js
index 5b746d6..e627ca5 100644
--- a/src/lib/standard/index.js
+++ b/src/lib/standard/index.js
@@ -6,7 +6,7 @@
  * Licensed under the LGPL2 license.
  */
 
-import jsonParser from './json/jsonparser';
+import jsonParser from './json/jsonparser.js';
 
 export default {
     jsonParser
diff --git a/src/lib/standard/json/jsonparser.js b/src/lib/standard/json/jsonparser.js
index 90d1931..502f427 100644
--- a/src/lib/standard/json/jsonparser.js
+++ b/src/lib/standard/json/jsonparser.js
@@ -6,10 +6,10 @@
  * Licensed under the LGPL2 license.
  */
 
-import {GenLex} from '../../genlex/genlex';
+import {GenLex} from '../../genlex/genlex.js';
+
+import {F,C,N} from '../../parsec/index.js';
 
-import {F} from '../../parsec/index';
-import {C, N} from "../../parsec";
 
 //
 // Facilities
diff --git a/src/lib/stream/arraystream.js b/src/lib/stream/arraystream.js
index 20fad77..a9a1b93 100644
--- a/src/lib/stream/arraystream.js
+++ b/src/lib/stream/arraystream.js
@@ -5,7 +5,7 @@
  * Copyright (c) 2016 Didier Plaindoux
  * Licensed under the LGPL2 license.
  */
-import Stream from './stream';
+import Stream from './stream.js';
 
 /**
  * Array stream class
diff --git a/src/lib/stream/bufferedstream.js b/src/lib/stream/bufferedstream.js
index 0b2e6b8..785bee9 100644
--- a/src/lib/stream/bufferedstream.js
+++ b/src/lib/stream/bufferedstream.js
@@ -5,7 +5,7 @@
  * Copyright (c) 2016 Didier Plaindoux
  * Licensed under the LGPL2 license.
  */
-import Stream from './stream';
+import Stream from './stream.js';
 
 /**
  * Buffered stream class
diff --git a/src/lib/stream/index.js b/src/lib/stream/index.js
index 440c8bc..81fb801 100644
--- a/src/lib/stream/index.js
+++ b/src/lib/stream/index.js
@@ -6,10 +6,10 @@
  * Licensed under the LGPL2 license.
  */
 
-import stringStreamFactory from './stringstream';
-import arrayStreamFactory from './arraystream';
-import parserStreamFactory from './parserstream';
-import bufferedStreamFactory from './bufferedstream';
+import stringStreamFactory from './stringstream.js';
+import arrayStreamFactory from './arraystream.js';
+import parserStreamFactory from './parserstream.js';
+import bufferedStreamFactory from './bufferedstream.js';
 
 export default {
     ofString: stringStreamFactory,
diff --git a/src/lib/stream/parserstream.js b/src/lib/stream/parserstream.js
index d75c09d..fe34302 100644
--- a/src/lib/stream/parserstream.js
+++ b/src/lib/stream/parserstream.js
@@ -6,8 +6,8 @@
  * Licensed under the LGPL2 license.
  */
 
-import Stream from './stream';
-import option from '../data/option';
+import Stream from './stream.js';
+import option from '../data/option.js';
 
 /**
  * ParserStream stream class
diff --git a/src/lib/stream/stream.js b/src/lib/stream/stream.js
index bf3b43c..9360534 100644
--- a/src/lib/stream/stream.js
+++ b/src/lib/stream/stream.js
@@ -6,7 +6,7 @@
  * Licensed under the LGPL2 license.
  */
 
-import atry from '../data/try';
+import atry from '../data/try.js';
 
 /**
  * Abstract methods:
diff --git a/src/lib/stream/stringstream.js b/src/lib/stream/stringstream.js
index 58b9065..6f34455 100644
--- a/src/lib/stream/stringstream.js
+++ b/src/lib/stream/stringstream.js
@@ -5,7 +5,7 @@
  * Copyright (c) 2016 Didier Plaindoux
  * Licensed under the LGPL2 license.
  */
-import Stream from './stream';
+import Stream from './stream.js';
 
 /**
  * String stream class