diff --git a/.gitignore b/.gitignore
index 7aa829d7c2..c712e3d5e9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,7 +22,7 @@ test/integration/dist/**/*.json
 test/integration/query/dist/fixtures.json
 */**/*.g.ts
 .eslintcache
-src/style-spec/dist/index.js
+src/style-spec/dist/index.cjs
 _batfish_site
 _batfish_tmp
 _site
diff --git a/rollup.config.style-spec.ts b/rollup.config.style-spec.ts
index 6f496782e3..1d8e9d5d84 100644
--- a/rollup.config.style-spec.ts
+++ b/rollup.config.style-spec.ts
@@ -14,7 +14,7 @@ const config: RollupOptions[] = [{
     input: 'src/style-spec/style-spec.ts',
     output: {
         name: 'maplibreGlStyleSpecification',
-        file: `dist/style-spec/${esm ? 'index.mjs' : 'index.js'}`,
+        file: `dist/style-spec/${esm ? 'index.mjs' : 'index.cjs'}`,
         format: esm ? 'esm' : 'umd',
         sourcemap: true
     },
diff --git a/src/style-spec/CHANGELOG.md b/src/style-spec/CHANGELOG.md
index 5d2cbf722b..e030228991 100644
--- a/src/style-spec/CHANGELOG.md
+++ b/src/style-spec/CHANGELOG.md
@@ -1,3 +1,9 @@
+## 16.0.0
+
+### Breaking changes
+
+* index.js has been renamed to index.cjs to fix the 'is treated as an ES module file' error in node 12+ [#1223](https://github.com/maplibre/maplibre-gl-js/pull/1223)
+
 ## 15.1.0
 
 ### ✨ Features and improvements
diff --git a/src/style-spec/package.json b/src/style-spec/package.json
index 3826c918ea..c5a1481349 100644
--- a/src/style-spec/package.json
+++ b/src/style-spec/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@maplibre/maplibre-gl-style-spec",
   "description": "a specification for maplibre gl styles",
-  "version": "15.1.0",
+  "version": "16.0.0",
   "author": "MapLibre",
   "keywords": [
     "mapbox",
@@ -12,7 +12,7 @@
     "maplibre-gl-js"
   ],
   "license": "ISC",
-  "main": "./dist/index.js",
+  "main": "./dist/index.cjs",
   "module": "./dist/index.mjs",
   "type": "module",
   "scripts": {
diff --git a/test/build/style-spec.test.ts b/test/build/style-spec.test.ts
index 0f5d748762..274ad4549e 100644
--- a/test/build/style-spec.test.ts
+++ b/test/build/style-spec.test.ts
@@ -2,7 +2,7 @@ import isBuiltin from 'is-builtin-module';
 import * as rollup from 'rollup';
 import rollupConfig from '../../rollup.config.style-spec';
 import styleSpecPackage from '../../src/style-spec/package.json';
-import * as spec from '../../dist/style-spec/index.js';
+import * as spec from '../../dist/style-spec/index.cjs';
 
 /* eslint-disable import/namespace */
 import {RollupOptions} from 'rollup';