diff --git a/apps/oxlint/src-js/js_config.ts b/apps/oxlint/src-js/js_config.ts
index 2010e71d4d749..0e98f8954b177 100644
--- a/apps/oxlint/src-js/js_config.ts
+++ b/apps/oxlint/src-js/js_config.ts
@@ -1,7 +1,6 @@
 import { basename as pathBasename } from "node:path";
 
 import { getErrorMessage } from "./utils/utils.ts";
-import { isDefineConfig } from "./package/config.ts";
 import { DateNow, JSONStringify } from "./utils/globals.ts";
 
 interface JsConfigResult {
@@ -135,12 +134,6 @@ export async function loadJsConfigs(paths: string[]): Promise<string> {
         if (!isObject(config)) {
           throw new Error(`Configuration file must have a default export that is an object.`);
         }
-
-        if (!isDefineConfig(config)) {
-          throw new Error(
-            `Configuration file must wrap its default export with defineConfig() from "oxlint".`,
-          );
-        }
         validateConfigExtends(config as object);
         return { path, config };
       }),
diff --git a/apps/oxlint/src-js/package/config.ts b/apps/oxlint/src-js/package/config.ts
index d4cc768f046cc..81ad7612c44dd 100644
--- a/apps/oxlint/src-js/package/config.ts
+++ b/apps/oxlint/src-js/package/config.ts
@@ -36,8 +36,6 @@ export interface OxlintConfig extends Oxlintrc {
 
 export type { OxlintOverride };
 
-const DEFINE_CONFIG_REGISTRY = new WeakSet<object>();
-
 /**
  * Define an Oxlint configuration with type inference.
  *
@@ -45,12 +43,5 @@ const DEFINE_CONFIG_REGISTRY = new WeakSet<object>();
  * @returns Config unchanged
  */
 export function defineConfig<T extends OxlintConfig>(config: T): T {
-  DEFINE_CONFIG_REGISTRY.add(config as object);
   return config;
 }
-
-export function isDefineConfig(config: unknown): boolean {
-  return (
-    typeof config === "object" && config !== null && DEFINE_CONFIG_REGISTRY.has(config as object)
-  );
-}
diff --git a/apps/oxlint/test/fixtures/js_config_missing_define_config/files/oxlint.config.ts b/apps/oxlint/test/fixtures/js_config_missing_define_config/files/oxlint.config.ts
deleted file mode 100644
index 4f00b08c16ffa..0000000000000
--- a/apps/oxlint/test/fixtures/js_config_missing_define_config/files/oxlint.config.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export default {
-  rules: {},
-};
diff --git a/apps/oxlint/test/fixtures/js_config_missing_define_config/files/test.js b/apps/oxlint/test/fixtures/js_config_missing_define_config/files/test.js
deleted file mode 100644
index 4f252c003683a..0000000000000
--- a/apps/oxlint/test/fixtures/js_config_missing_define_config/files/test.js
+++ /dev/null
@@ -1 +0,0 @@
-console.log("ok");
diff --git a/apps/oxlint/test/fixtures/js_config_missing_define_config/output.snap.md b/apps/oxlint/test/fixtures/js_config_missing_define_config/output.snap.md
deleted file mode 100644
index dc461dcfb657a..0000000000000
--- a/apps/oxlint/test/fixtures/js_config_missing_define_config/output.snap.md
+++ /dev/null
@@ -1,15 +0,0 @@
-# Exit code
-1
-
-# stdout
-```
-Failed to parse oxlint configuration file.
-
-  x Failed to load config: <fixture>/files/oxlint.config.ts
-  | 
-  | Error: Configuration file must wrap its default export with defineConfig() from "oxlint".
-```
-
-# stderr
-```
-```