diff --git a/lib/config.js b/lib/config.js
index 552776a..c555b6e 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -23,6 +23,10 @@ function removeEmpty (obj) {
   return _.omit(obj, _.isEmpty)
 }
 
+function ensureLeadingSlash (path) {
+  return path.length && path[0] !== '/' ? '/' + path : path
+}
+
 /**
  * Parse a boolean config variable.
  *
@@ -78,12 +82,7 @@ function parseServerConfig (prefix) {
   let port = parseInt(getEnv(prefix, 'PORT'), 10) || 3000
   let public_host = getEnv(prefix, 'HOSTNAME') || require('os').hostname()
   let public_port = parseInt(getEnv(prefix, 'PUBLIC_PORT'), 10) || port
-  let public_path = getEnv(prefix, 'PUBLIC_PATH') || ''
-
-  // Ensure path starts with a slash
-  if (public_path.length && public_path[0] !== '/') {
-    public_path = '/' + public_path
-  }
+  const public_path = ensureLeadingSlash(getEnv(prefix, 'PUBLIC_PATH') || '')
 
   if (useTestConfig()) {
     public_host = 'localhost'