diff --git a/.eslintrc.json b/.eslintrc.json
index 0985a7d..d8dd055 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -21,6 +21,7 @@
     "Set": true
   },
   "rules": {
+    "no-trailing-spaces": [2],
     "no-unused-vars": [ "error", {
       "vars": "all",
       "args": "after-used",
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b265949..7034e6f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
  * 2.6.1 _???.??.2023_
    * [update README to work w/ eslint-plugin-markdown](https://github.com/iambumblehead/esmock/pull/275)
+   * [update eslint](https://github.com/iambumblehead/esmock/pull/276) disallow trailing whitespace
  * 2.6.0 _Nov.07.2023_
    * [typings: make MockFunction generic,](https://github.com/iambumblehead/esmock/pull/267) thanks @uwinkelvos
  * 2.5.9 _Nov.01.2023_
diff --git a/src/esmock.d.ts b/src/esmock.d.ts
index 6e17319..e8e35b0 100644
--- a/src/esmock.d.ts
+++ b/src/esmock.d.ts
@@ -93,5 +93,5 @@ export {
   type MockFunction,
   type MockMap,
   type Options,
-  type Resolver   
+  type Resolver
 }
diff --git a/src/esmockModule.js b/src/esmockModule.js
index 214b0af..31ade8f 100644
--- a/src/esmockModule.js
+++ b/src/esmockModule.js
@@ -24,7 +24,7 @@ const isJSONExtnRe = /\.json$/i
 
 // assigning the object to its own prototypal inheritor can error, eg
 //   'Cannot assign to read only property \'F_OK\' of object \'#<Object>\''
-// 
+//
 // if not plain obj, assign enumerable vals only. core modules === plain obj
 const esmockModuleMerge = (defLive, def) => isPlainObj(defLive)
   ? Object.assign({}, defLive, def)
diff --git a/tests/local/pnp/enable.js b/tests/local/pnp/enable.js
index bbbbd68..0da6644 100644
--- a/tests/local/pnp/enable.js
+++ b/tests/local/pnp/enable.js
@@ -6,7 +6,7 @@ async function resolve (specifier, context, next) {
       ? '../tests/local/pnp/api.js'
       : specifier, context)
 }
-  
+
 module.register && (process.versions.pnp = '3') && module.register(`
 data:text/javascript,
 export ${encodeURIComponent(resolve)}`.slice(1))
diff --git a/tests/tests-node/esmock.node.resolver-pnp.test.js b/tests/tests-node/esmock.node.resolver-pnp.test.js
index 02825ce..ffac726 100644
--- a/tests/tests-node/esmock.node.resolver-pnp.test.js
+++ b/tests/tests-node/esmock.node.resolver-pnp.test.js
@@ -20,7 +20,7 @@ test.beforeEach(() => {
 test('should work with pnp resolver', async ({ mock }) => {
   if (!module.register)
     return assert.ok('skip test')
-  
+
   pnpapi.resolveRequest = mock.fn(resolver)
 
   const main = await esmock('../local/main.js', {
diff --git a/tests/tests-node/esmock.node.test.js b/tests/tests-node/esmock.node.test.js
index 8b02f1f..60952c1 100644
--- a/tests/tests-node/esmock.node.test.js
+++ b/tests/tests-node/esmock.node.test.js
@@ -559,7 +559,7 @@ test('should mock imported json', async () => {
 
   if (/^(18|20)$/.test(process.versions.node.split('.')[0]))
     return assert.ok(true)
-  
+
   assert.strictEqual(
     Object.keys(importsJSON.JSONobj).sort().join(), 'example,test-example')
   assert.strictEqual(importsJSON.JSONobj['test-example'], 'test-json-a')
@@ -576,7 +576,7 @@ test('should mock imported json (strict)', async () => {
 
   if (/^(18|20)$/.test(process.versions.node.split('.')[0]))
     return assert.ok(true)
-  
+
   assert.strictEqual(
     Object.keys(importsJSON.JSONobj).sort().join(), 'test-example')
   assert.strictEqual(importsJSON.JSONobj['test-example'], 'test-json-b')