diff --git a/.changeset/beige-carrots-care.md b/.changeset/beige-carrots-care.md
new file mode 100644
index 0000000000..fbb2d6a1f1
--- /dev/null
+++ b/.changeset/beige-carrots-care.md
@@ -0,0 +1,5 @@
+---
+"@medusajs/js-sdk": patch
+---
+
+fix(js-sdk): allow passing custom request body parameters in auth.register method
diff --git a/packages/core/js-sdk/src/auth/index.ts b/packages/core/js-sdk/src/auth/index.ts
index a6c6378876..70a7a179ad 100644
--- a/packages/core/js-sdk/src/auth/index.ts
+++ b/packages/core/js-sdk/src/auth/index.ts
@@ -48,7 +48,7 @@ export class Auth {
   register = async (
     actor: string,
     method: string,
-    payload: HttpTypes.AdminSignUpWithEmailPassword
+    payload: HttpTypes.AdminSignUpWithEmailPassword | Record<string, unknown>
   ) => {
     const { token } = await this.client.fetch<{ token: string }>(
       `/auth/${actor}/${method}/register`,