diff --git a/thomson-problem.js b/thomson-problem.js
index 8b8245c..bb7466c 100644
--- a/thomson-problem.js
+++ b/thomson-problem.js
@@ -1,5 +1,5 @@
 function move_charges(charges) {
-  for (charge of charges) {
+  for (let charge of charges) {
     charge.acceleration.setMag(0);
   }
   for (let i = 0; i < charges.length; i += 1) {
@@ -23,8 +23,7 @@ function move_charges(charges) {
       charges[j].acceleration.add(aj);
     }
   }
-  for (let i = 0; i < charges.length; i += 1) {
-    let charge = charges[i];
+  for (let charge of charges) {
     charge.velocity = charge.velocity.add(charge.acceleration);
     charge.position = charge.position.add(charge.velocity);
     charge.position.normalize();