diff --git a/packages/next/src/withPayload.js b/packages/next/src/withPayload.js
index a52c131de0e..fff14cabe1f 100644
--- a/packages/next/src/withPayload.js
+++ b/packages/next/src/withPayload.js
@@ -146,9 +146,6 @@ export const withPayload = (nextConfig = {}) => {
   if (nextConfig.basePath) {
     toReturn.env.NEXT_BASE_PATH = nextConfig.basePath
   }
-  if (nextConfig.assetPrefix) {
-    toReturn.env.NEXT_ASSET_PREFIX = nextConfig.assetPrefix
-  }
 
   return toReturn
 }
diff --git a/packages/payload/src/index.ts b/packages/payload/src/index.ts
index 0c9b38b9f07..6df1409955c 100644
--- a/packages/payload/src/index.ts
+++ b/packages/payload/src/index.ts
@@ -883,7 +883,9 @@ export const getPayload = async (
         const port = process.env.PORT || '3000'
 
         const path = '/_next/webpack-hmr'
-        const prefix = process.env.NEXT_BASE_PATH ?? process.env.NEXT_ASSET_PREFIX ?? ''
+        // The __NEXT_ASSET_PREFIX env variable is set for both assetPrefix and basePath (tested in Next.js 15.1.6)
+        const prefix = process.env.__NEXT_ASSET_PREFIX ?? ''
+
         cached.ws = new WebSocket(
           process.env.PAYLOAD_HMR_URL_OVERRIDE ?? `ws://localhost:${port}${prefix}${path}`,
         )