diff --git a/packages/vite/src/node/plugins/clientInjections.ts b/packages/vite/src/node/plugins/clientInjections.ts
index da59527c66b0e6..347d413922e70d 100644
--- a/packages/vite/src/node/plugins/clientInjections.ts
+++ b/packages/vite/src/node/plugins/clientInjections.ts
@@ -40,21 +40,20 @@ export function clientInjectionsPlugin(config: ResolvedConfig): Plugin {
           port = path.posix.normalize(`${port}${hmrBase}`)
         }
 
+        const defines = {
+          'process.env.NODE_ENV': JSON.stringify(config.mode),
+          ...(config.define || {})
+        }
+
         return code
           .replace(`__MODE__`, JSON.stringify(config.mode))
           .replace(`__BASE__`, JSON.stringify(config.base))
-          .replace(`__DEFINES__`, serializeDefine(config.define || {}))
+          .replace(`__DEFINES__`, serializeDefine(defines))
           .replace(`__HMR_PROTOCOL__`, JSON.stringify(protocol))
           .replace(`__HMR_HOSTNAME__`, JSON.stringify(host))
           .replace(`__HMR_PORT__`, JSON.stringify(port))
           .replace(`__HMR_TIMEOUT__`, JSON.stringify(timeout))
           .replace(`__HMR_ENABLE_OVERLAY__`, JSON.stringify(overlay))
-      } else if (code.includes('process.env.NODE_ENV')) {
-        // replace process.env.NODE_ENV
-        return code.replace(
-          /\bprocess\.env\.NODE_ENV\b/g,
-          JSON.stringify(config.mode)
-        )
       }
     }
   }