diff --git a/.env.example b/.env.example
index f5a60b2b..0fd7c17d 100644
--- a/.env.example
+++ b/.env.example
@@ -36,10 +36,10 @@ APP_URL=http://localhost
 
 
 # If you want to serve js assets from a CDN (like https://cdn.example.com),
-# you need to set this custom URL here.
-# Otherwise, this should be the exact same value as APP_URL.
+# uncomment the following line and set this var with the CDN url.
+# Otherwise, let this line commented.
 
-ASSET_URL=http://localhost
+# ASSET_URL=http://localhost
 
 
 # The domain subdirectory from which you want to serve 2FAuth.
diff --git a/Dockerfile b/Dockerfile
index dc05844c..c6ed307a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -125,9 +125,10 @@ ENV \
     # Webauthn won't work otherwise.
     APP_URL=http://localhost \
     # If you want to serve js assets from a CDN (like https://cdn.example.com),
-    # you need to set this custom URL here.
-    # Otherwise, this should be the exact same value as APP_URL.
-    ASSET_URL=http://localhost \
+    # uncomment the following line and set this var with the CDN url.
+    # Otherwise, let this line commented.
+    # ASSET_URL=http://localhost \
+    #
     # Turn this to true if you want your app to react like a demo.
     # The Demo mode reset the app content every hours and set a generic demo user.
     IS_DEMO_APP=false \
diff --git a/config/app.php b/config/app.php
index 88fb6364..73fdda48 100644
--- a/config/app.php
+++ b/config/app.php
@@ -3,6 +3,8 @@
 use Illuminate\Support\Facades\Facade;
 use Illuminate\Support\ServiceProvider;
 
+$appUrl = env('APP_URL', env('HEROKU_APP_NAME') ? 'https://' . env('HEROKU_APP_NAME') . '.herokuapp.com' : 'http://localhost');
+
 return [
 
     /*
@@ -55,9 +57,9 @@
     |
     */
 
-    'url' => env('APP_URL', env('HEROKU_APP_NAME') ? 'https://' . env('HEROKU_APP_NAME') . '.herokuapp.com' : 'http://localhost'),
+    'url' => $appUrl,
 
-    'asset_url' => env('ASSET_URL', null),
+    'asset_url' => env('ASSET_URL', $appUrl),
 
     /*
     |--------------------------------------------------------------------------
diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
index 66cfaf32..e909d975 100644
--- a/docker/docker-compose.yml
+++ b/docker/docker-compose.yml
@@ -25,9 +25,10 @@ services:
       # Webauthn won't work otherwise.
       - APP_URL=http://localhost
       # If you want to serve js assets from a CDN (like https://cdn.example.com),
-      # you need to set this custom URL here.
-      # Otherwise, this should be the exact same value as APP_URL.
-      - ASSET_URL=http://localhost
+      # uncomment the following line and set this var with the CDN url.
+      # Otherwise, let this line commented.
+      # - ASSET_URL=http://localhost
+      #
       # Turn this to true if you want your app to react like a demo.
       # The Demo mode reset the app content every hours and set a generic demo user.
       - IS_DEMO_APP=false