diff --git a/js/mod.ts b/js/mod.ts
index 8d638ec..da4a4ad 100644
--- a/js/mod.ts
+++ b/js/mod.ts
@@ -1,7 +1,5 @@
-import {
-  instantiate,
-  type JsLockfile,
-} from "./deno_lockfile_wasm.generated.js";
+import * as wasm from "./deno_lockfile_wasm.generated.js";
+import { type JsLockfile } from "./deno_lockfile_wasm.generated.d.ts";
 
 export interface WorkspaceMemberConfig {
   dependencies?: string[];
@@ -36,7 +34,8 @@ export interface NpmPackageInfo {
   dependencies: Record<string, string>;
 }
 
-export interface Lockfile extends Omit<JsLockfile, "copy" | "filename" | "free"> {
+export interface Lockfile
+  extends Omit<JsLockfile, "copy" | "filename" | "free"> {
   copy(): Lockfile;
   insertNpmPackage(specifier: string, packageInfo: NpmPackageInfo): void;
   setWorkspaceConfig(config: WorkspaceConfig): void;
@@ -48,14 +47,36 @@ export async function parseFromJson(
   baseUrl: string | URL,
   json: string | LockfileJson,
 ): Promise<Lockfile> {
-  const wasm = await instantiate();
+  return parseFromJsonWith(baseUrl, json, await wasm.instantiate());
+}
+
+export interface InstanciateResult {
+  parseFromJson(baseUrl: string | URL, json: string | LockfileJson): Lockfile;
+}
+
+export async function instantiate(
+  opts?: wasm.InstantiateOptions,
+): Promise<InstanciateResult> {
+  const mod = await wasm.instantiate(opts);
+  return {
+    parseFromJson(baseUrl, json) {
+      return parseFromJsonWith(baseUrl, json, mod);
+    },
+  };
+}
+
+function parseFromJsonWith(
+  baseUrl: string | URL,
+  json: string | LockfileJson,
+  mod: Awaited<ReturnType<typeof wasm.instantiate>>,
+): Lockfile {
   if (baseUrl instanceof URL) {
     baseUrl = baseUrl.toString();
   }
   if (typeof json === "object") {
     json = JSON.stringify(json);
   }
-  const inner = wasm.parseFromJson(baseUrl, json);
+  const inner = mod.parseFromJson(baseUrl, json);
   return new Proxy(inner, {
     get(target, prop, receiver) {
       if (prop === "filename") {
diff --git a/js/test.ts b/js/test.ts
index 1826afa..ff22074 100644
--- a/js/test.ts
+++ b/js/test.ts
@@ -5,7 +5,7 @@ import {
   assertObjectMatch,
 } from "@std/assert";
 import { beforeEach, describe, it } from "@std/testing/bdd";
-import { Lockfile, parseFromJson } from "./mod.ts";
+import { instantiate, Lockfile, parseFromJson } from "./mod.ts";
 
 describe("parseFromJson", () => {
   const json = {
@@ -40,6 +40,19 @@ describe("parseFromJson", () => {
   });
 });
 
+describe("instantiate", () => {
+  it("should return a synchronous interface to parseFromJson", async () => {
+    const wasm = await instantiate();
+    assertEquals(
+      wasm.parseFromJson("file:///deno.lock", { version: "3" }).toJson(),
+      {
+        version: "3",
+        remote: {},
+      },
+    );
+  });
+});
+
 describe("LockFile", () => {
   describe("filename", () => {
     it("should return the filename", async () => {