diff --git a/test/order/barycenter-test.js b/test/order/barycenter-test.js
index 53a8fa59..2a949926 100644
--- a/test/order/barycenter-test.js
+++ b/test/order/barycenter-test.js
@@ -1,9 +1,9 @@
-var expect = require("../chai").expect;
-var barycenter = require("../../lib/order/barycenter");
-var Graph = require("@dagrejs/graphlib").Graph;
+let expect = require("../chai").expect;
+let barycenter = require("../../lib/order/barycenter");
+let Graph = require("@dagrejs/graphlib").Graph;
 
 describe("order/barycenter", () => {
-  var g;
+  let g;
 
   beforeEach(() => {
     g = new Graph()
@@ -14,7 +14,7 @@ describe("order/barycenter", () => {
   it("assigns an undefined barycenter for a node with no predecessors", () => {
     g.setNode("x", {});
 
-    var results = barycenter(g, ["x"]);
+    let results = barycenter(g, ["x"]);
     expect(results).to.have.length(1);
     expect(results[0]).to.eql({ v: "x" });
   });
@@ -23,7 +23,7 @@ describe("order/barycenter", () => {
     g.setNode("a", { order: 2 });
     g.setEdge("a", "x");
 
-    var results = barycenter(g, ["x"]);
+    let results = barycenter(g, ["x"]);
     expect(results).to.have.length(1);
     expect(results[0]).eqls({ v: "x", barycenter: 2, weight: 1 });
   });
@@ -34,7 +34,7 @@ describe("order/barycenter", () => {
     g.setEdge("a", "x");
     g.setEdge("b", "x");
 
-    var results = barycenter(g, ["x"]);
+    let results = barycenter(g, ["x"]);
     expect(results).to.have.length(1);
     expect(results[0]).eqls({ v: "x", barycenter: 3, weight: 2 });
   });
@@ -45,7 +45,7 @@ describe("order/barycenter", () => {
     g.setEdge("a", "x", { weight: 3 });
     g.setEdge("b", "x");
 
-    var results = barycenter(g, ["x"]);
+    let results = barycenter(g, ["x"]);
     expect(results).to.have.length(1);
     expect(results[0]).eqls({ v: "x", barycenter: 2.5, weight: 4 });
   });
@@ -60,7 +60,7 @@ describe("order/barycenter", () => {
     g.setEdge("a", "z", { weight: 2 });
     g.setEdge("c", "z");
 
-    var results = barycenter(g, ["x", "y", "z"]);
+    let results = barycenter(g, ["x", "y", "z"]);
     expect(results).to.have.length(3);
     expect(results[0]).eqls({ v: "x", barycenter: 1.5, weight: 2 });
     expect(results[1]).eqls({ v: "y" });