diff --git a/src/entries/basic.mjs b/src/entries/basic.js
similarity index 100%
rename from src/entries/basic.mjs
rename to src/entries/basic.js
diff --git a/src/entries/devserver.mjs b/src/entries/devserver.js
similarity index 100%
rename from src/entries/devserver.mjs
rename to src/entries/devserver.js
diff --git a/src/index.js b/src/index.js
index 371dfdb..c1db18e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,7 +1,7 @@
 const errorOverlayMiddleware = require('react-dev-utils/errorOverlayMiddleware')
 
-const chunkPathBasic = require.resolve('./entries/basic.mjs')
-const chunkPathDevServer = require.resolve('./entries/devserver.mjs')
+const chunkPathBasic = require.resolve('./entries/basic')
+const chunkPathDevServer = require.resolve('./entries/devserver')
 
 class ErrorOverlayPlugin {
   apply(compiler) {