diff --git a/packages/babel-plugin-transform-es2015-parameters/src/destructuring.js b/packages/babel-plugin-transform-es2015-parameters/src/destructuring.js
index 65f8ed22d7..e3a7e10494 100644
--- a/packages/babel-plugin-transform-es2015-parameters/src/destructuring.js
+++ b/packages/babel-plugin-transform-es2015-parameters/src/destructuring.js
@@ -6,9 +6,10 @@ export let visitor = {
 
     // If there's a rest param, no need to loop through it. Also, we need to
     // hoist one more level to get `declar` at the right spot.
-    const hoistTweak = t.isRestElement(params[params.length - 1]) ? 1 : 0;
+    let hoistTweak = t.isRestElement(params[params.length - 1]) ? 1 : 0;
+    let outputParamsLength = params.length - hoistTweak;
 
-    for (let i = 0; i < params.length - hoistTweak; i++) {
+    for (let i = 0; i < outputParamsLength; i++) {
       let param = params[i];
       if (param.isArrayPattern() || param.isObjectPattern()) {
         let uid = path.scope.generateUidIdentifier("ref");
@@ -16,7 +17,7 @@ export let visitor = {
         let declar = t.variableDeclaration("let", [
           t.variableDeclarator(param.node, uid)
         ]);
-        declar._blockHoist = params.length - i - hoistTweak;
+        declar._blockHoist = outputParamsLength - i;
 
         path.ensureBlock();
         path.get("body").unshiftContainer("body", declar);