diff --git a/packages/vite/src/node/env.ts b/packages/vite/src/node/env.ts
index 6f807c46268b59..d5c58089dab167 100644
--- a/packages/vite/src/node/env.ts
+++ b/packages/vite/src/node/env.ts
@@ -52,7 +52,9 @@ export function loadEnv(
 
   // let environment variables use each other
   expand({
-    parsed
+    parsed,
+    // prevent process.env mutation
+    ignoreProcessEnv: true
   })
 
   // only keys that start with prefix are exposed to client