diff --git a/caddy/letsencrypt/letsencrypt.go b/caddy/letsencrypt/letsencrypt.go
index a7aef7e8..093a4eb6 100644
--- a/caddy/letsencrypt/letsencrypt.go
+++ b/caddy/letsencrypt/letsencrypt.go
@@ -158,7 +158,7 @@ func newClient(leEmail string) (*acme.Client, error) {
 	}
 
 	// The client facilitates our communication with the CA server.
-	client := acme.NewClient(caURL, &leUser, rsaKeySizeToUse, exposePort)
+	client := acme.NewClient(CAUrl, &leUser, rsaKeySizeToUse, exposePort)
 
 	// If not registered, the user must register an account with the CA
 	// and agree to terms
@@ -331,15 +331,13 @@ var (
 
 	// Whether user has agreed to the Let's Encrypt SA
 	Agreed bool
+
+	// The base URL to the CA's ACME endpoint
+	CAUrl string
 )
 
 // Some essential values related to the Let's Encrypt process
 const (
-	// The base URL to the Let's Encrypt CA
-	// TODO: Staging API URL is: https://acme-staging.api.letsencrypt.org
-	// TODO: Production endpoint is: https://acme-v01.api.letsencrypt.org
-	caURL = "http://192.168.99.100:4000"
-
 	// The port to expose to the CA server for Simple HTTP Challenge
 	exposePort = "5001"
 
diff --git a/main.go b/main.go
index 15d39de5..aa3ed0d8 100644
--- a/main.go
+++ b/main.go
@@ -29,16 +29,20 @@ const (
 
 func init() {
 	flag.StringVar(&conf, "conf", "", "Configuration file to use (default="+caddy.DefaultConfigFile+")")
-	flag.BoolVar(&caddy.HTTP2, "http2", true, "Enable HTTP/2 support") // TODO: temporary flag until http2 merged into std lib
+	flag.BoolVar(&caddy.HTTP2, "http2", true, "HTTP/2 support") // TODO: temporary flag until http2 merged into std lib
 	flag.BoolVar(&caddy.Quiet, "quiet", false, "Quiet mode (no initialization output)")
 	flag.StringVar(&cpu, "cpu", "100%", "CPU cap")
 	flag.StringVar(&caddy.Root, "root", caddy.DefaultRoot, "Root path to default site")
 	flag.StringVar(&caddy.Host, "host", caddy.DefaultHost, "Default host")
 	flag.StringVar(&caddy.Port, "port", caddy.DefaultPort, "Default port")
 	flag.BoolVar(&version, "version", false, "Show version")
+	// TODO: Boulder dev URL is: http://192.168.99.100:4000
+	// TODO: Staging API URL is: https://acme-staging.api.letsencrypt.org
+	// TODO: Production endpoint is: https://acme-v01.api.letsencrypt.org
+	flag.StringVar(&letsencrypt.CAUrl, "ca", "https://acme-staging.api.letsencrypt.org", "Certificate authority ACME server")
 	flag.BoolVar(&letsencrypt.Agreed, "agree", false, "Agree to Let's Encrypt Subscriber Agreement")
 	flag.StringVar(&letsencrypt.DefaultEmail, "email", "", "Default email address to use for Let's Encrypt transactions")
-	flag.StringVar(&revoke, "revoke", "", "Hostname for which to revoke its certificate")
+	flag.StringVar(&revoke, "revoke", "", "Hostname for which to revoke the certificate")
 }
 
 func main() {