diff --git a/src/index.js b/src/index.js
index 412953c..3f9a7fe 100644
--- a/src/index.js
+++ b/src/index.js
@@ -8,7 +8,7 @@ const matchImport = /^([\w-]+)(?:\s+as\s+([\w-]+))?/;
 
 module.exports = (options) => {
   let importIndex = 0;
-  let createImportedName =
+  const createImportedName =
     (options && options.createImportedName) ||
     ((importName /*, path*/) =>
       `i__const_${importName.replace(/\W/g, "_")}_${importIndex++}`);