diff --git a/composer.lock b/composer.lock
index 3f75b721826..fdddc728f8c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -269,12 +269,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/mnapoli/PHP-DI.git",
-                "reference": "27341c05b930e3768f19f4c4b20eec14ce84bd06"
+                "reference": "d7f54f3c1b3523493eb5f4b5ca38bcfd74d96169"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/mnapoli/PHP-DI/zipball/27341c05b930e3768f19f4c4b20eec14ce84bd06",
-                "reference": "27341c05b930e3768f19f4c4b20eec14ce84bd06",
+                "url": "https://api.github.com/repos/mnapoli/PHP-DI/zipball/d7f54f3c1b3523493eb5f4b5ca38bcfd74d96169",
+                "reference": "d7f54f3c1b3523493eb5f4b5ca38bcfd74d96169",
                 "shasum": ""
             },
             "require": {
@@ -299,10 +299,8 @@
                 }
             },
             "autoload": {
-                "psr-0": {
-                    "DI\\": "src/",
-                    "IntegrationTests\\": "tests/",
-                    "UnitTests\\": "tests/"
+                "psr-4": {
+                    "DI\\": "src/DI/"
                 },
                 "files": [
                     "src/DI/functions.php"
@@ -319,7 +317,7 @@
                 "dependency injection",
                 "di"
             ],
-            "time": "2014-11-12 03:18:24"
+            "time": "2014-12-11 22:24:18"
         },
         {
             "name": "mnapoli/phpdocreader",
diff --git a/core/Container/IniConfigDefinitionSource.php b/core/Container/IniConfigDefinitionSource.php
index b84d33d94f6..5d4518196bd 100644
--- a/core/Container/IniConfigDefinitionSource.php
+++ b/core/Container/IniConfigDefinitionSource.php
@@ -9,16 +9,14 @@
 namespace Piwik\Container;
 
 use DI\Definition\Exception\DefinitionException;
-use DI\Definition\MergeableDefinition;
 use DI\Definition\Source\ChainableDefinitionSource;
-use DI\Definition\Source\DefinitionSource;
 use DI\Definition\ValueDefinition;
 use Piwik\Config;
 
 /**
  * Import the old INI config into PHP-DI.
  */
-class IniConfigDefinitionSource implements DefinitionSource, ChainableDefinitionSource
+class IniConfigDefinitionSource extends ChainableDefinitionSource
 {
     /**
      * @var Config
@@ -30,11 +28,6 @@ class IniConfigDefinitionSource implements DefinitionSource, ChainableDefinition
      */
     private $prefix;
 
-    /**
-     * @var DefinitionSource
-     */
-    private $chainedSource;
-
     /**
      * @param Config $config
      * @param string $prefix Prefix for the container entries.
@@ -45,15 +38,10 @@ public function __construct(Config $config, $prefix = 'old_config.')
         $this->prefix = $prefix;
     }
 
-    public function getDefinition($name, MergeableDefinition $parentDefinition = null)
+    protected function findDefinition($name)
     {
-        // INI only contains values, so no definition merging here
-        if ($parentDefinition) {
-            return $this->notFound($name, $parentDefinition);
-        }
-
         if (strpos($name, $this->prefix) !== 0) {
-            return $this->notFound($name, $parentDefinition);
+            return null;
         }
 
         list($sectionName, $configKey) = $this->parseEntryName($name);
@@ -65,17 +53,12 @@ public function getDefinition($name, MergeableDefinition $parentDefinition = nul
         }
 
         if (! array_key_exists($configKey, $section)) {
-            return $this->notFound($name, $parentDefinition);
+            return null;
         }
 
         return new ValueDefinition($name, $section[$configKey]);
     }
 
-    public function chain(DefinitionSource $source)
-    {
-        $this->chainedSource = $source;
-    }
-
     private function parseEntryName($name)
     {
         $parts = explode('.', $name, 3);
@@ -102,13 +85,4 @@ private function getSection($sectionName)
 
         return $section;
     }
-
-    private function notFound($name, $parentDefinition)
-    {
-        if ($this->chainedSource) {
-            return $this->chainedSource->getDefinition($name, $parentDefinition);
-        }
-
-        return null;
-    }
 }