diff --git a/.esmrc b/.esmrc
new file mode 100644
index 0000000..c404743
--- /dev/null
+++ b/.esmrc
@@ -0,0 +1,8 @@
+{
+  cjs: {
+    // Ensure ESM `export default` ends up as the root, e.g. `module.exports` when
+    // being `require()`d from CJS code. This is not spec compliant, but that does
+    // not matter because only use this `esm` package trickery locally while testing
+    dedefault: true
+  }
+}
diff --git a/package-lock.json b/package-lock.json
index a3438bd..2a09067 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2178,6 +2178,12 @@
       "integrity": "sha512-8y9YjtM1JBJU/A9Kc+SbaOV4y29sSWckBwMHa+FGtVj5gN/sbnKDf6xJUl+8g7FAij9LVaP8C24DUiH/f/2Z9A==",
       "dev": true
     },
+    "esm": {
+      "version": "3.2.25",
+      "resolved": "https://registry.npmjs.org/esm/-/esm-3.2.25.tgz",
+      "integrity": "sha512-U1suiZ2oDVWv4zPO56S0NcR5QriEahGtdN2OR6FiOG4WJvcjBVFB0qI4+eKoWFH483PKGuLuu6V8Z4T5g63UVA==",
+      "dev": true
+    },
     "espree": {
       "version": "6.1.2",
       "resolved": "https://registry.npmjs.org/espree/-/espree-6.1.2.tgz",
@@ -2905,7 +2911,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -2926,12 +2933,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2946,17 +2955,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -3073,7 +3085,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -3085,6 +3098,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -3099,6 +3113,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -3106,12 +3121,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -3130,6 +3147,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -3210,7 +3228,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -3222,6 +3241,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -3307,7 +3327,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -3343,6 +3364,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -3362,6 +3384,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -3405,12 +3428,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
diff --git a/package.json b/package.json
index 48c4a5f..71312e0 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "build": "cp mustache.js mustache.mjs && rollup mustache.mjs --file mustache.js --format umd --name Mustache && uglifyjs mustache.js > mustache.min.js",
     "test": "npm run test-lint && npm run test-unit",
     "test-lint": "eslint mustache.js bin/mustache test/**/*.js",
-    "test-unit": "mocha --reporter spec test/*-test.js",
+    "test-unit": "mocha --reporter spec --require esm test/*-test.js",
     "test-render": "mocha  --reporter spec test/render-test",
     "pre-test-browser": "node test/create-browser-suite.js",
     "test-browser": "npm run pre-test-browser && zuul -- test/context-test.js test/parse-test.js test/scanner-test.js test/render-test-browser.js",
@@ -41,6 +41,7 @@
   "devDependencies": {
     "chai": "^3.4.0",
     "eslint": "^6.5.1",
+    "esm": "^3.2.25",
     "jshint": "^2.9.5",
     "mocha": "^3.0.2",
     "puppeteer": "^2.0.0",
diff --git a/test/cli-test.js b/test/cli-test.js
index b409179..6f7d2f8 100644
--- a/test/cli-test.js
+++ b/test/cli-test.js
@@ -9,10 +9,10 @@ var cliPartialsTxt = path.resolve(_files, 'cli_with_partials.txt');
 var moduleVersion = require('../package').version;
 
 function changeForOS (command) {
+  command = command.replace('bin/mustache', 'node --require esm bin/mustache')
 
   if (process.platform === 'win32') {
     return command
-      .replace(/bin\/mustache/g, 'node bin\\mustache')
       .replace(/\bcat\b/g, 'type')
       .replace(/\//g, '\\');
   }