diff --git a/packages-exp/messaging-exp/src/helpers/isSupported.ts b/packages-exp/messaging-exp/src/helpers/isSupported.ts
index c73122eaad1..2c7c0618fdc 100644
--- a/packages-exp/messaging-exp/src/helpers/isSupported.ts
+++ b/packages-exp/messaging-exp/src/helpers/isSupported.ts
@@ -15,20 +15,10 @@
  * limitations under the License.
  */
 
-export function isSupported(): boolean {
-  if (self && 'ServiceWorkerGlobalScope' in self) {
-    // Running in ServiceWorker context
-    return isSWControllerSupported();
-  } else {
-    // Assume we are in the window context.
-    return isWindowControllerSupported();
-  }
-}
-
 /**
  * Checks to see if the required APIs exist.
  */
-function isWindowControllerSupported(): boolean {
+export function isWindowSupported(): boolean {
   return (
     'indexedDB' in window &&
     indexedDB !== null &&
@@ -45,7 +35,7 @@ function isWindowControllerSupported(): boolean {
 /**
  * Checks to see if the required APIs exist within SW Context.
  */
-function isSWControllerSupported(): boolean {
+export function isSwSupported(): boolean {
   return (
     'indexedDB' in self &&
     indexedDB !== null &&
diff --git a/packages-exp/messaging-exp/src/helpers/register.ts b/packages-exp/messaging-exp/src/helpers/registerMessaging.ts
similarity index 86%
rename from packages-exp/messaging-exp/src/helpers/register.ts
rename to packages-exp/messaging-exp/src/helpers/registerMessaging.ts
index cb6b99259bb..367e7781b3f 100644
--- a/packages-exp/messaging-exp/src/helpers/register.ts
+++ b/packages-exp/messaging-exp/src/helpers/registerMessaging.ts
@@ -21,19 +21,13 @@ import {
   ComponentType,
   InstanceFactory
 } from '@firebase/component';
-import { ERROR_FACTORY, ErrorCode } from '../util/errors';
 
 import { MessagingService } from '../messaging-service';
 import { _registerComponent } from '@firebase/app-exp';
-import { isSupported } from './isSupported';
 
 const messagingFactory: InstanceFactory<'messaging-exp'> = (
   container: ComponentContainer
 ) => {
-  if (!isSupported()) {
-    throw ERROR_FACTORY.create(ErrorCode.UNSUPPORTED_BROWSER);
-  }
-
   return new MessagingService(
     container.getProvider('app-exp').getImmediate(),
     container.getProvider('installations-exp-internal').getImmediate(),
diff --git a/packages-exp/messaging-exp/src/index.sw.ts b/packages-exp/messaging-exp/src/index.sw.ts
index 75e588fc62a..2862fb783cb 100644
--- a/packages-exp/messaging-exp/src/index.sw.ts
+++ b/packages-exp/messaging-exp/src/index.sw.ts
@@ -15,10 +15,17 @@
  * limitations under the License.
  */
 
+
 import { FirebaseMessaging } from './interfaces/public-types';
 import { registerMessaging } from './helpers/register';
 import '@firebase/installations-exp';
 
+import { ERROR_FACTORY, ErrorCode } from './util/errors';
+
+import { FirebaseMessaging } from '@firebase/messaging-types-exp';
+import { isSwSupported } from './helpers/isSupported';
+import { registerMessaging } from './helpers/registerMessaging';
+
 export { onBackgroundMessage, getMessaging } from './api';
 
 declare module '@firebase/component' {
@@ -27,4 +34,8 @@ declare module '@firebase/component' {
   }
 }
 
+if (!isSwSupported()) {
+  throw ERROR_FACTORY.create(ErrorCode.UNSUPPORTED_BROWSER);
+}
+
 registerMessaging();
diff --git a/packages-exp/messaging-exp/src/index.ts b/packages-exp/messaging-exp/src/index.ts
index fd12f5b4867..004574cdcae 100644
--- a/packages-exp/messaging-exp/src/index.ts
+++ b/packages-exp/messaging-exp/src/index.ts
@@ -28,4 +28,8 @@ declare module '@firebase/component' {
   }
 }
 
+if (!isWindowSupported()) {
+  throw ERROR_FACTORY.create(ErrorCode.UNSUPPORTED_BROWSER);
+}
+
 registerMessaging();