diff --git a/src/__tests__/utils/request-router.test.ts b/src/__tests__/utils/request-router.test.ts
index 9116b2116..887f16307 100644
--- a/src/__tests__/utils/request-router.test.ts
+++ b/src/__tests__/utils/request-router.test.ts
@@ -19,11 +19,19 @@ describe('request-router', () => {
         ['https://us.posthog.com', 'ui', 'https://us.posthog.com'],
         ['https://us.posthog.com', 'assets', 'https://us-assets.i.posthog.com'],
         ['https://us.posthog.com', 'api', 'https://us.i.posthog.com'],
+        ['https://us.i.posthog.com', 'api', 'https://us.i.posthog.com'],
+        ['https://us.i.posthog.com', 'assets', 'https://us-assets.i.posthog.com'],
+        ['https://us-assets.i.posthog.com', 'assets', 'https://us-assets.i.posthog.com'],
+        ['https://us-assets.i.posthog.com', 'api', 'https://us.i.posthog.com'],
 
         // EU domain
         ['https://eu.posthog.com', 'ui', 'https://eu.posthog.com'],
         ['https://eu.posthog.com', 'assets', 'https://eu-assets.i.posthog.com'],
         ['https://eu.posthog.com', 'api', 'https://eu.i.posthog.com'],
+        ['https://eu.i.posthog.com', 'api', 'https://eu.i.posthog.com'],
+        ['https://eu.i.posthog.com', 'assets', 'https://eu-assets.i.posthog.com'],
+        ['https://eu-assets.i.posthog.com', 'assets', 'https://eu-assets.i.posthog.com'],
+        ['https://eu-assets.i.posthog.com', 'api', 'https://eu.i.posthog.com'],
 
         // custom domain
         ['https://my-custom-domain.com', 'ui', 'https://my-custom-domain.com'],
diff --git a/src/utils/request-router.ts b/src/utils/request-router.ts
index 7838c37f4..83f50d808 100644
--- a/src/utils/request-router.ts
+++ b/src/utils/request-router.ts
@@ -16,6 +16,7 @@ export type RequestRouterTarget = 'api' | 'ui' | 'assets'
 
 export class RequestRouter {
     instance: PostHog
+    private _regionCache: Record<string, RequestRouterRegion> = {}
 
     constructor(instance: PostHog) {
         this.instance = instance
@@ -29,15 +30,17 @@ export class RequestRouter {
     }
 
     get region(): RequestRouterRegion {
-        switch (this.apiHost) {
-            case 'https://app.posthog.com':
-            case 'https://us.posthog.com':
-                return RequestRouterRegion.US
-            case 'https://eu.posthog.com':
-                return RequestRouterRegion.EU
-            default:
-                return RequestRouterRegion.CUSTOM
+        // We don't need to compute this every time so we cache the result
+        if (!this._regionCache[this.apiHost]) {
+            if (/https:\/\/(app|us|us-assets)(\.i)?\.posthog\.com/i.test(this.apiHost)) {
+                this._regionCache[this.apiHost] = RequestRouterRegion.US
+            } else if (/https:\/\/(eu|eu-assets)(\.i)?\.posthog\.com/i.test(this.apiHost)) {
+                this._regionCache[this.apiHost] = RequestRouterRegion.EU
+            } else {
+                this._regionCache[this.apiHost] = RequestRouterRegion.CUSTOM
+            }
         }
+        return this._regionCache[this.apiHost]
     }
 
     endpointFor(target: RequestRouterTarget, path: string = ''): string {