diff --git a/packages/build-tools/package-lock.json b/packages/build-tools/package-lock.json
index d0482478..589970a6 100644
--- a/packages/build-tools/package-lock.json
+++ b/packages/build-tools/package-lock.json
@@ -1,16 +1,16 @@
 {
   "name": "@spinframework/build-tools",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@spinframework/build-tools",
-      "version": "1.0.3",
+      "version": "1.0.4",
       "license": "Apache-2.0 WITH LLVM-exception",
       "dependencies": {
         "@ampproject/remapping": "^2.3.0",
-        "@bytecodealliance/componentize-js": "^0.19.0",
+        "@bytecodealliance/componentize-js": "^0.19.2",
         "@bytecodealliance/jco": "^1.10.2",
         "acorn-walk": "^8.3.4",
         "acron": "^1.0.5",
@@ -49,9 +49,9 @@
       }
     },
     "node_modules/@bytecodealliance/componentize-js": {
-      "version": "0.19.0",
-      "resolved": "https://registry.npmjs.org/@bytecodealliance/componentize-js/-/componentize-js-0.19.0.tgz",
-      "integrity": "sha512-xiwg4rh7JPj9uPTcAdj7axSnMRgyp/f5qKKbPRQn9mafASPytgNyhg7YwjcAtX17HiiZGjgGrZCXh+FmLSBbjA==",
+      "version": "0.19.2",
+      "resolved": "https://registry.npmjs.org/@bytecodealliance/componentize-js/-/componentize-js-0.19.2.tgz",
+      "integrity": "sha512-8gzP4mRNkRF7frCf8NChbx0MHKf13VRiDupVF4B9VeTRNBJsLabRXvwaE71Qwe4dB7ZUsD1Rv09anWF12e3XgQ==",
       "workspaces": [
         "."
       ],
diff --git a/packages/build-tools/package.json b/packages/build-tools/package.json
index da87a795..8f95ca69 100644
--- a/packages/build-tools/package.json
+++ b/packages/build-tools/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@spinframework/build-tools",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "",
   "main": "index.js",
   "scripts": {
@@ -30,7 +30,7 @@
   },
   "dependencies": {
     "@ampproject/remapping": "^2.3.0",
-    "@bytecodealliance/componentize-js": "^0.19.0",
+    "@bytecodealliance/componentize-js": "^0.19.2",
     "@bytecodealliance/jco": "^1.10.2",
     "acorn-walk": "^8.3.4",
     "acron": "^1.0.5",
diff --git a/packages/build-tools/src/cli.ts b/packages/build-tools/src/cli.ts
index e5635ee4..866ef6e1 100644
--- a/packages/build-tools/src/cli.ts
+++ b/packages/build-tools/src/cli.ts
@@ -6,6 +6,7 @@ export interface CliArgs {
   output: string;
   aot?: boolean;
   debug?: boolean;
+  initLocation?: string;
 }
 
 export function getCliArgs(): CliArgs {
@@ -30,6 +31,10 @@ export function getCliArgs(): CliArgs {
       describe: 'Enable JavaScript debugging',
       type: 'boolean',
     })
+    .option('initLocation', {
+      describe: 'Location during top level initialization',
+      type: 'string',
+    })
     .argv as CliArgs;
 
   return args;
diff --git a/packages/build-tools/src/index.ts b/packages/build-tools/src/index.ts
index 17885c76..184ff2d5 100644
--- a/packages/build-tools/src/index.ts
+++ b/packages/build-tools/src/index.ts
@@ -26,7 +26,10 @@ async function main() {
     let CliArgs = getCliArgs();
     let src = CliArgs.input;
     let outputPath = CliArgs.output;
-    let runtimeArgs = CliArgs.debug ? '--enable-script-debugging' : '';
+    let runtimeArgs = [
+      CliArgs.debug && '--enable-script-debugging',
+      CliArgs.initLocation && `--init-location ${CliArgs.initLocation}`
+    ].filter(Boolean).join(' ');
 
     // generate wit world string
     let wasiDeps = getPackagesWithWasiDeps(process.cwd(), new Set(), true);
diff --git a/test/test-app/package-lock.json b/test/test-app/package-lock.json
index f54ea1b9..0f7e1d77 100644
--- a/test/test-app/package-lock.json
+++ b/test/test-app/package-lock.json
@@ -24,11 +24,11 @@
     },
     "../../packages/build-tools": {
       "name": "@spinframework/build-tools",
-      "version": "1.0.3",
+      "version": "1.0.4",
       "license": "Apache-2.0 WITH LLVM-exception",
       "dependencies": {
         "@ampproject/remapping": "^2.3.0",
-        "@bytecodealliance/componentize-js": "^0.19.0",
+        "@bytecodealliance/componentize-js": "^0.19.2",
         "@bytecodealliance/jco": "^1.10.2",
         "acorn-walk": "^8.3.4",
         "acron": "^1.0.5",
diff --git a/test/test-app/package.json b/test/test-app/package.json
index e5061f36..96725dde 100644
--- a/test/test-app/package.json
+++ b/test/test-app/package.json
@@ -7,7 +7,7 @@
   "keywords": [],
   "license": "Apache-2.0",
   "scripts": {
-    "build": "node build.mjs && mkdirp dist && j2w -i build/bundle.js -o dist/test-app.wasm",
+    "build": "node build.mjs && mkdirp dist && j2w -i build/bundle.js -o dist/test-app.wasm --initLocation http://foo.bar",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "devDependencies": {
diff --git a/test/test-app/src/index.ts b/test/test-app/src/index.ts
index 92929a6d..2fd124ae 100644
--- a/test/test-app/src/index.ts
+++ b/test/test-app/src/index.ts
@@ -1,6 +1,13 @@
 import { AutoRouter } from "itty-router"
 import { headersTest, health, kvTest, kvTestUint8Array, outboundHttp, statusTest, stream, streamTest, testFunctionality } from "./test";
 
+// Verify top level init location
+if (globalThis.location.href != "http://foo.bar/") {
+    throw new Error(`Expected top-level init location to be "http://foo.bar/", got "${globalThis.location}"`);
+} else {
+    console.log(`Top-level init location verified:, ${globalThis.location.href}`);
+}
+
 let router = AutoRouter()
 
 router.get("/health", health)