diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
index 6a4505a5..6c460186 100644
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 15.x]
+        node-version: [12.x, 14.x, 16.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:
diff --git a/README.md b/README.md
index e7a7e768..8e158cfb 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ esmock
   "type": "module",
   "scripts": {
     "test-ava": "ava --node-arguments=\"--loader=esmock\"",
-    "test-mocha": "mocha --loader=esmock"
+    "test-mocha": "mocha --loader=esmock --no-warnings"
   }
 }
 ```
@@ -24,12 +24,15 @@ import esmock from 'esmock';
 test('should mock modules and local files at same time', async t => {
   const main = await esmock('../src/main.js', {
     stringifierpackage : o => JSON.stringify(o),
+    '../src/hello.js' : {
+      default : () => 'world'
+    },
     '../src/util.js' : {
       exportedFunction : () => 'foobar'
     }
   });
 
-  t.is(main(), JSON.stringify({ test : 'foobar' }));
+  t.is(main(), JSON.stringify({ test : 'world foobar' }));
 });
 
 test('should do global instance mocks —third parameter', async t => {
@@ -48,6 +51,9 @@ test('should do global instance mocks —third parameter', async t => {
 
 ### changelog
 
+ * 0.3.9 _May.05.2021_
+   * small change to README
+   * added a test, update gitlab action to use node 16.x
  * 0.3.8 _Apr.21.2021_
    * small change to README
  * 0.3.7 _Apr.20.2021_
diff --git a/package.json b/package.json
index ee57a32e..e98d4472 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "esmock",
-  "version": "0.3.8",
+  "version": "0.3.9",
   "license": "MIT",
   "readmeFilename": "README.md",
   "description": "mock esm modules for unit-tests",
diff --git a/spec/esmock.spec.js b/spec/esmock.spec.js
index db0ab1bd..2988cbd4 100644
--- a/spec/esmock.spec.js
+++ b/spec/esmock.spec.js
@@ -205,6 +205,16 @@ test('should mock an mjs file, again', async t => {
   t.is(main.verifyImportedMock(), 'second mocked');
 });
 
+test('should mock an exported constant values', async t => {
+  const main = await esmock('./local/usesmjsModule.js', {
+    './local/env.js' : {
+      TESTCONSTANT : 'hello world'
+    }
+  });
+
+  t.is(main.verifyImportedConstant(), 'hello world');
+});
+
 test('should mock core module', async t => {
   const usesCoreModule = await esmock('./local/usesCoreModule.js', {
     fs : {
diff --git a/spec/local/env.js b/spec/local/env.js
new file mode 100644
index 00000000..67caa0cc
--- /dev/null
+++ b/spec/local/env.js
@@ -0,0 +1,2 @@
+
+export const TESTCONSTANT = 'TESTCONSTANTVALUE';
diff --git a/spec/local/usesmjsModule.js b/spec/local/usesmjsModule.js
index 18b3bd91..2caba241 100644
--- a/spec/local/usesmjsModule.js
+++ b/spec/local/usesmjsModule.js
@@ -1,5 +1,10 @@
 import scheduleFunction from './exampleMJS.mjs';
+import { TESTCONSTANT } from './env.js';
 
 export function verifyImportedMock () {
   return scheduleFunction();
 }
+
+export function verifyImportedConstant () {
+  return TESTCONSTANT;
+}