diff --git a/imports/i18n/i18n.test.js b/imports/i18n/i18n.test.js
new file mode 100644
index 000000000..c51d4a525
--- /dev/null
+++ b/imports/i18n/i18n.test.js
@@ -0,0 +1,130 @@
+import { Tracker } from 'meteor/tracker';
+import chai, { expect } from 'chai';
+import sinon from 'sinon';
+import { TAPi18n } from './tap';
+
+chai.use(require('sinon-chai'));
+chai.use(require('chai-as-promised'));
+
+describe('TAPi18n', () => {
+
+  beforeEach(() => {
+    sinon.stub(console, 'log');
+  });
+
+  afterEach(() => {
+    sinon.restore();
+  });
+
+  if (Meteor.isClient) {
+    it('extra languages are not loaded initially', () => {
+      // Using function here to prevent Meteor from including the file
+      // during building time
+      function path(language) {
+        return `./data/${language}.i18n.json`;
+      }
+      expect(() => require(path('de'))).to.throw('Cannot find module');
+    });
+  }
+
+  describe('.init', () => {
+
+    it('has default language translation loaded', async () => {
+      sinon.spy(TAPi18n, 'loadLanguage');
+      await TAPi18n.init();
+      expect(TAPi18n.loadLanguage).to.be.calledWith('en');
+      expect(TAPi18n.getLanguage()).to.be.equal('en');
+      expect(TAPi18n.__('accept')).to.be.equal('Accept');
+    });
+
+  });
+
+  describe('.getSupportedLanguages', () => {
+
+    it('returns an array of objects with expected structure', () => {
+      const languages = TAPi18n.getSupportedLanguages();
+      expect(languages).to.be.an('array');
+      for (const language of languages) {
+        expect(language).to.have.keys('name', 'code', 'isoCode');
+      }
+    });
+
+  });
+
+  describe('.getLanguage', () => {
+
+    it('is reactive', async () => {
+      const tracked = [];
+      Tracker.autorun(() => {
+        tracked.push(TAPi18n.getLanguage());
+      });
+      expect(tracked).to.have.members(['en']);
+      await TAPi18n.setLanguage('de');
+      Tracker.flush();
+      expect(tracked).to.have.members(['en', 'de']);
+    });
+
+  });
+
+  describe('.loadLanguage', () => {
+
+    beforeEach(() => {
+      sinon.stub(TAPi18n.i18n, 'addResourceBundle');
+    });
+
+    it('actually loads the language data', async () => {
+      await TAPi18n.loadLanguage('fr');
+      expect(TAPi18n.i18n.addResourceBundle).to.be.calledOnceWith('fr');
+      expect(TAPi18n.i18n.addResourceBundle.firstCall.args[2]).to.have.property('accept');
+    });
+
+    it('does nothing if language is missing', async () => {
+      await expect(TAPi18n.loadLanguage('miss')).to.be.fulfilled;
+      expect(TAPi18n.i18n.addResourceBundle).to.not.be.called;
+    });
+
+  });
+
+  describe('.__', () => {
+
+    beforeEach(async () => {
+      await TAPi18n.init();
+      TAPi18n.i18n.addResourceBundle('fr', 'translation', {
+        'simple': 'Hello',
+        'positional': 'Hello, %s! How is your %s?',
+        'named': 'Hello, __whom__! How is your __what__?',
+      });
+      TAPi18n.i18n.changeLanguage('fr');
+    });
+
+    it('works with simple keys', () => {
+      const result = TAPi18n.__('simple');
+      expect(result).to.be.equal('Hello');
+    });
+
+    it('works with simple keys and custom language', async () => {
+      TAPi18n.i18n.addResourceBundle('de', 'translation', {
+        'simple': 'Hola',
+      });
+      const result = TAPi18n.__('simple', null, 'de');
+      expect(result).to.be.equal('Hola');
+    });
+
+    it('works with positional parameters', () => {
+      const result = TAPi18n.__('positional', {
+        sprintf: ['Josh', 'life']
+      });
+      expect(result).to.be.equal('Hello, Josh! How is your life?');
+    });
+
+    it('works with named parameters', () => {
+      const result = TAPi18n.__('named', {
+        whom: 'Annie',
+        what: 'job'
+      });
+      expect(result).to.be.equal('Hello, Annie! How is your job?');
+    });
+
+  });
+
+});
diff --git a/tests/main.js b/tests/main.js
index 648be68c2..1f83ffb5b 100644
--- a/tests/main.js
+++ b/tests/main.js
@@ -17,6 +17,8 @@
 // they are. However, if you want to restict tests to server-only or client-only
 // you need to wrap them inside a new describe-block
 
+import '/imports/i18n/i18n.test.js';
+
 if (Meteor.isServer) {
   describe('server', function() {
     import '../server/lib/tests/utils.tests';