diff --git a/lib/rangy-classapplier.js b/lib/rangy-classapplier.js
index 9fe90d85..11f17a2b 100644
--- a/lib/rangy-classapplier.js
+++ b/lib/rangy-classapplier.js
@@ -741,7 +741,7 @@
 
                 // Apply the merges
                 if (merges.length) {
-                    for (i = 0, len = merges.length; i < len; ++i) {
+                    for (let i = 0, len = merges.length; i < len; ++i) {
                         merges[i].doMerge(positionsToPreserve);
                     }