diff --git a/.changeset/all-sheep-wear.md b/.changeset/all-sheep-wear.md
new file mode 100644
index 00000000..a915c0e7
--- /dev/null
+++ b/.changeset/all-sheep-wear.md
@@ -0,0 +1,5 @@
+---
+'@kitql/eslint-config': minor
+---
+
+[BREAKING] switch .prettierrc.mjs to .prettierrc.js
diff --git a/.prettierrc.mjs b/.prettierrc.js
similarity index 84%
rename from .prettierrc.mjs
rename to .prettierrc.js
index 74d1db07..ca5789ae 100644
--- a/.prettierrc.mjs
+++ b/.prettierrc.js
@@ -1,4 +1,4 @@
-import { kitql } from './packages/eslint-config/.prettierrc.mjs'
+import { kitql } from './packages/eslint-config/.prettierrc.js'
 
 export default {
 	...kitql(),
diff --git a/docs/src/content/docs/docs/tools/08_eslint-config.mdx b/docs/src/content/docs/docs/tools/08_eslint-config.mdx
index 078a5c70..e9936f80 100644
--- a/docs/src/content/docs/docs/tools/08_eslint-config.mdx
+++ b/docs/src/content/docs/docs/tools/08_eslint-config.mdx
@@ -56,8 +56,8 @@ npx @eslint/config-inspector
 ### prettier config
 
 ```js
-// .prettierrc.mjs
-import { kitql } from '@kitql/eslint-config/.prettierrc.mjs'
+// .prettierrc.js
+import { kitql } from '@kitql/eslint-config/.prettierrc.js'
 
 export default {
 	...kitql(),
diff --git a/packages/eslint-config/.prettierrc.mjs b/packages/eslint-config/.prettierrc.js
similarity index 100%
rename from packages/eslint-config/.prettierrc.mjs
rename to packages/eslint-config/.prettierrc.js
diff --git a/packages/eslint-config/cmd.js b/packages/eslint-config/cmd.js
index 226ef125..426a0b44 100755
--- a/packages/eslint-config/cmd.js
+++ b/packages/eslint-config/cmd.js
@@ -40,7 +40,7 @@ program.parse(process.argv)
 const options_cli = program.opts()
 
 const pathPrettierIgnore = findFileOrUp('.prettierignore')
-const pathPrettierMjs = findFileOrUp('.prettierrc.mjs')
+const pathPrettier_js = findFileOrUp('.prettierrc.js')
 
 const format = options_cli.format ?? false
 let glob = options_cli.glob ?? '.'
@@ -294,7 +294,7 @@ async function prettierRun() {
 		// ignore?
 		` --ignore-path ${pathPrettierIgnore}` +
 		// config
-		` --config ${pathPrettierMjs}` +
+		` --config ${pathPrettier_js}` +
 		// format or not
 		`${format ? ' --write' : ''}` +
 		// exec
diff --git a/packages/eslint-config/package.json b/packages/eslint-config/package.json
index 9dfb2da3..6729fffd 100644
--- a/packages/eslint-config/package.json
+++ b/packages/eslint-config/package.json
@@ -17,7 +17,7 @@
   },
   "main": "eslint.config.js",
   "files": [
-    ".prettierrc.mjs",
+    ".prettierrc.js",
     "cmd.js",
     "eslint.config.js",
     "helper/findFileOrUp.js"