diff --git a/packages/react-scripts/scripts/build.js b/packages/react-scripts/scripts/build.js
index 8cd1ad77ee5..1803e260af2 100644
--- a/packages/react-scripts/scripts/build.js
+++ b/packages/react-scripts/scripts/build.js
@@ -143,7 +143,7 @@ checkBrowsers(paths.appPath, isInteractive)
 function build(previousFileSizes) {
   console.log('Creating an optimized production build...');
 
-  let compiler = webpack(config);
+  const compiler = webpack(config);
   return new Promise((resolve, reject) => {
     compiler.run((err, stats) => {
       let messages;