diff --git a/installer/check.php b/installer/check.php
index 7ca982f2d..2afa7da29 100644
--- a/installer/check.php
+++ b/installer/check.php
@@ -37,7 +37,7 @@ echo '<input type="hidden" name="_step" value="' . ($RCI->configured ? 3 : 2) .
 <h3>Checking PHP version</h3>
 <?php
 
-define('MIN_PHP_VERSION', '5.2.0');
+define('MIN_PHP_VERSION', '4.3.1');
 if (version_compare(PHP_VERSION, MIN_PHP_VERSION, '>=')) {
     $RCI->pass('Version', 'PHP ' . PHP_VERSION . ' detected');
 } else {