diff --git a/.changeset/ninety-terms-build.md b/.changeset/ninety-terms-build.md
new file mode 100644
index 000000000000..40ac0ff49aad
--- /dev/null
+++ b/.changeset/ninety-terms-build.md
@@ -0,0 +1,5 @@
+---
+"@rspack/cli": patch
+---
+
+add defineConfig helper
diff --git a/packages/rspack-cli/src/index.ts b/packages/rspack-cli/src/index.ts
index 0ce6c22001bc..075c83aac5b3 100644
--- a/packages/rspack-cli/src/index.ts
+++ b/packages/rspack-cli/src/index.ts
@@ -1,3 +1,3 @@
 import { IRspackCLI } from "./types";
 export * from "./types";
-export { RspackCLI } from "./rspack-cli";
+export { RspackCLI, defineConfig } from "./rspack-cli";
diff --git a/packages/rspack-cli/src/rspack-cli.ts b/packages/rspack-cli/src/rspack-cli.ts
index 1d613cfb4385..d4b94f54c380 100644
--- a/packages/rspack-cli/src/rspack-cli.ts
+++ b/packages/rspack-cli/src/rspack-cli.ts
@@ -229,3 +229,7 @@ export class RspackCLI {
 		return Boolean((compiler as MultiCompiler).compilers);
 	}
 }
+
+export function defineConfig(config: RspackOptions): RspackOptions {
+	return config;
+}