diff --git a/docs/Changelog.md b/docs/Changelog.md
index 952af0d..221fb71 100644
--- a/docs/Changelog.md
+++ b/docs/Changelog.md
@@ -2,7 +2,8 @@
 
 Released November --, 2015
 
-- Internal changes and updated dependencies.
+- Internal changes and updated dependencies
+- `New` PHP-version-check now requires PHP >= 5.5
 - `New` Preloading of big photos (#185)
 
 ## v3.0.6
diff --git a/docs/Installation.md b/docs/Installation.md
index 895e916..045b0fb 100644
--- a/docs/Installation.md
+++ b/docs/Installation.md
@@ -1,5 +1,5 @@
 ### 1. Requirements
-Everything you need is a web-server with PHP 5.3 or later and a MySQL-Database.
+Everything you need is a web-server with PHP 5.5 or later and a MySQL-Database.
 
 The following PHP extensions must be activated:
 
diff --git a/plugins/check/index.php b/plugins/check/index.php
index 36f0e16..2bf149c 100644
--- a/plugins/check/index.php
+++ b/plugins/check/index.php
@@ -26,7 +26,7 @@ echo('Diagnostics' . PHP_EOL);
 echo('-----------' . PHP_EOL);
 
 # PHP Version
-if (floatval(phpversion())<5.3)		$error .= ('Error: Upgrade to PHP 5.3 or higher' . PHP_EOL);
+if (floatval(phpversion())<5.5)		$error .= ('Error: Upgrade to PHP 5.5 or higher' . PHP_EOL);
 
 # Extensions
 if (!extension_loaded('session'))	$error .= ('Error: PHP session extension not activated' . PHP_EOL);