diff --git a/DependencyInjection/DependencyInjection.php b/DependencyInjection/Configuration.php
similarity index 57%
rename from DependencyInjection/DependencyInjection.php
rename to DependencyInjection/Configuration.php
index e4693e9..f972bb6 100644
--- a/DependencyInjection/DependencyInjection.php
+++ b/DependencyInjection/Configuration.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace DesignPatterns;
+namespace DesignPatterns\DependencyInjection;
 
 /**
  * Dependency Injection
@@ -18,15 +18,20 @@ namespace DesignPatterns;
  */
 class Configuration
 {
-    protected $_host;
+    /**
+     * @var string
+     */
+    protected $host;
 
     /**
      * @param string $host
+     *
      * @return Configuration
      */
     public function setHost($host)
     {
-        $this->_host = $host;
+        $this->host = $host;
+
         return $this; // for a fluent interface
     }
 
@@ -35,29 +40,6 @@ class Configuration
      */
     public function getHost()
     {
-        return $this->_host;
-    }
-}
-
-class Connection
-{
-    protected $_configuration;
-
-    /**
-     * here, Configuration gets injected and Connection will get all that it needs from Configuration
-     * without DI, the configuration would be created directly in Connection, which is not very good
-     * for testing and extending Connection
-     *
-     * @param Configuration $config
-     */
-    public function __construct(Configuration $config)
-    {
-        $this->_configuration = $config;
-    }
-
-    public function connect()
-    {
-        $host = $this->_configuration->getHost();
-        // ...
+        return $this->host;
     }
 }
diff --git a/DependencyInjection/Connection.php b/DependencyInjection/Connection.php
new file mode 100644
index 0000000..02ff81b
--- /dev/null
+++ b/DependencyInjection/Connection.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace DesignPatterns\DependencyInjection;
+
+/**
+ * Class Connection
+ */
+class Connection
+{
+    /**
+     * @var Configuration
+     */
+    protected $configuration;
+
+    /**
+     * here, Configuration gets injected and Connection will get all that it needs from Configuration
+     * without DI, the configuration would be created directly in Connection, which is not very good
+     * for testing and extending Connection
+     *
+     * @param Configuration $config
+     */
+    public function __construct(Configuration $config)
+    {
+        $this->configuration = $config;
+    }
+
+    /**
+     * connection using the injected config
+     */
+    public function connect()
+    {
+        $host = $this->configuration->getHost();
+        // ...
+    }
+}