diff --git a/docs/site/scripts/sync-algolia.ts b/docs/site/scripts/sync-algolia.ts
index 2dd45bb77bb55..99befffb9dbd7 100644
--- a/docs/site/scripts/sync-algolia.ts
+++ b/docs/site/scripts/sync-algolia.ts
@@ -35,12 +35,24 @@ const algoliaClient = algosearch(
   process.env.ALGOLIA_API_KEY
 );
 
+// Ensure a non-production target environment cannot sync to a production-looking Algolia index
+if (
+  process.env.VERCEL_TARGET_ENV !== "production" &&
+  process.env.NEXT_PUBLIC_ALGOLIA_INDEX?.includes("production")
+) {
+  throw new Error(
+    "Writing to the production Algolia index when building for an environment that is not production is not permitted."
+  );
+}
+
 const getDomain = () => {
-  if (process.env.VERCEL_ENV === "production") {
+  // Only "Production" environment
+  if (process.env.VERCEL_TARGET_ENV === "production") {
     return `https://${process.env.VERCEL_PROJECT_PRODUCTION_URL}`;
   }
 
-  if (process.env.VERCEL_ENV === "preview") {
+  // All other environments on Vercel (Previews and Custom Environments)
+  if (process.env.VERCEL_ENV) {
     return `https://${process.env.VERCEL_URL}`;
   }