diff --git a/php/1-bad-practices/src/calling-static-methods.php b/php/1-bad-practices/src/calling-static-methods.php
index eac75e7..87e1976 100644
--- a/php/1-bad-practices/src/calling-static-methods.php
+++ b/php/1-bad-practices/src/calling-static-methods.php
@@ -1,10 +1,25 @@
 <?php # -*- coding: utf-8 -*-
 
+class Checker {
+
+	public function is_okay( $data ) {
+
+		return ThirdPartyChecker::is_okay( $data );
+	}
+}
+
 class Renderer {
 
+	private $checker;
+
+	public function __construct( Checker $checker ) {
+
+		$this->checker = $checker;
+	}
+
 	public function render_if_okay( $data ) {
 
-		if ( ThirdPartyChecker::is_okay( $data ) ) {
+		if ( $this->checker->is_okay( $data ) ) {
 			echo $data;
 		}
 	}