diff --git a/lib/6to5/transformation/transformers/es7-array-comprehension.js b/lib/6to5/transformation/transformers/es7-array-comprehension.js
index becf836007..a988678d93 100644
--- a/lib/6to5/transformation/transformers/es7-array-comprehension.js
+++ b/lib/6to5/transformation/transformers/es7-array-comprehension.js
@@ -49,7 +49,7 @@ exports._build = function (node, buildBody) {
   }
 
   return t.forOfStatement(
-    t.variableDeclaration("var", [t.variableDeclarator(self.left)]),
+    t.variableDeclaration("let", [t.variableDeclarator(self.left)]),
     self.right,
     t.blockStatement([child])
   );