diff --git a/README.md b/README.md
index 78eb694..5635456 100644
--- a/README.md
+++ b/README.md
@@ -72,14 +72,35 @@ in your sample app:
 cp .env.example .env
 ```
 
-### Configure your MongoDB Credentials
+### Set the Default Connection Environment Variable
 
-In your ``.env`` file, set or update the following variables, replacing the
-``<connection string>`` placeholder with your MongoDB connection string:
+Open the ``.env`` file in an editor and set the value of the ``DB_CONNECTION``
+variable to ``mongodb`` as shown in the following example:
 
 ```
 DB_CONNECTION=mongodb
-DB_URI=<connection string>
+```
+
+### Make a Copy of the Example Environment File
+
+Run the following command to use the example environment file
+in your sample app:
+
+```
+cp .env.example .env
+```
+
+### Configure your MongoDB Credentials
+
+In the ``.env`` file, replace the value of the ``DB_URI`` variable with your
+MongoDB connection string.
+
+For example, if your connection string is
+"mongodb+srv://myUser:myPass123@mongo0.example.com/",
+your ``DB_URI`` variable matches the following line:
+
+```
+DB_URI="mongodb+srv://myUser:myPass123@mongo0.example.com/"
 ```
 
 If you need to create a MongoDB Atlas deployment, see the
@@ -90,6 +111,9 @@ If you already have a MongoDB Atlas deployment, see the
 [Create a Connection String](https://www.mongodb.com/docs/drivers/php/laravel-mongodb/current/quick-start/create-a-connection-string)
 step of the Quick Start.
 
+> [!NOTE]
+> Make sure these variables in your ``.env`` file are undefined in the shell in which you run your application. Environment variables in the shell take precedence over the ones in the ``.env`` file.
+
 ### Start the PHP Built-in Webserver
 
 To start the webserver, run the following command from the application root
diff --git a/my-app/config/database.php b/my-app/config/database.php
index 368ed5a..59510b5 100644
--- a/my-app/config/database.php
+++ b/my-app/config/database.php
@@ -16,7 +16,7 @@
     |
     */
 
-    'default' => env('DB_CONNECTION', 'mongodb'),
+    'default' => env('DB_CONNECTION'),
 
     /*
     |--------------------------------------------------------------------------
@@ -32,7 +32,7 @@
     'connections' => [
         'mongodb' => [
           'driver' => 'mongodb',
-          'dsn' => env('DB_URI', '<connection string>'),
+          'dsn' => env('DB_URI'),
           'database' => 'sample_mflix',
         ],