diff --git a/lib/examples/e2e-testing/calculator_test.go b/lib/examples/e2e-testing/calculator_test.go
index 70a40cc8..fc9c72aa 100644
--- a/lib/examples/e2e-testing/calculator_test.go
+++ b/lib/examples/e2e-testing/calculator_test.go
@@ -3,11 +3,13 @@ package main
 
 import "testing"
 
-// test case: 1 + 2 = 3
+const appURL = "https://go-rod.github.io/calculator/"
+
+// test case: 1 + 2 = 3.
 func TestAdd(t *testing.T) {
 	g := setup(t)
 
-	p := g.page("https://ahfarmer.github.io/calculator")
+	p := g.page(appURL)
 
 	p.MustElementR("button", "1").MustClick()
 	p.MustElementR("button", `^\+$`).MustClick()
@@ -18,11 +20,11 @@ func TestAdd(t *testing.T) {
 	g.Eq(p.MustElement(".component-display").MustText(), "3")
 }
 
-// test case: 2 * 3 = 6
+// test case: 2 * 3 = 6.
 func TestMultiple(t *testing.T) {
 	g := setup(t)
 
-	p := g.page("https://ahfarmer.github.io/calculator")
+	p := g.page(appURL)
 
 	// use for-loop to click each button
 	for _, regex := range []string{"2", "x", "3", "="} {
diff --git a/lib/examples/e2e-testing/setup_test.go b/lib/examples/e2e-testing/setup_test.go
index be8ef74c..d7debf41 100644
--- a/lib/examples/e2e-testing/setup_test.go
+++ b/lib/examples/e2e-testing/setup_test.go
@@ -9,14 +9,14 @@ import (
 	"github.com/ysmood/got"
 )
 
-// test context
+// test context.
 type G struct {
 	got.G
 
 	browser *rod.Browser
 }
 
-// setup for tests
+// setup for tests.
 var setup = func() func(t *testing.T) G {
 	browser := rod.New().MustConnect()
 
@@ -27,7 +27,7 @@ var setup = func() func(t *testing.T) G {
 	}
 }()
 
-// a helper function to create an incognito page
+// a helper function to create an incognito page.
 func (g G) page(url string) *rod.Page {
 	page := g.browser.MustIncognito().MustPage(url)
 	g.Cleanup(page.MustClose)