diff --git a/composer.json b/composer.json
index 3d507c1..3931d21 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,7 @@
     "name": "petermolnar/wp-flatbackups",
     "description": "WordPress plugin to auto-export WordPress content to flat YAML + HTML files",
     "require": {
-		"php": ">=5.3.0",
+        "php": ">=5.3.0",
         "ext-yaml": "^1.2"
     },
     "license": "GPLv3",
@@ -10,7 +10,7 @@
         {
             "name": "Peter Molnar",
             "email": "hello@petermolnar.eu",
-			"homepage": "https://petermolnar.eu"
+            "homepage": "https://petermolnar.eu"
         }
     ]
 }
diff --git a/readme.txt b/readme.txt
index 662edb6..b3d0c2e 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,6 +1,6 @@
 === wp-flatbackups ===
 Contributors: cadeyrn
-Donate link:
+Donate link: https://paypal.me/petermolnar/3
 Tags: backup, YAML, flat files
 Requires at least: 3.0
 Tested up to: 4.4
diff --git a/wp-flatbackups.php b/wp-flatbackups.php
index c613b71..fe21e3d 100644
--- a/wp-flatbackups.php
+++ b/wp-flatbackups.php
@@ -31,12 +31,21 @@ if (!class_exists('WP_FLATBACKUPS')):
 class WP_FLATBACKUPS {
 
 	public function __construct () {
-		if (!function_exists('yaml_emit')) {
-			static::debug('`yaml_emit` function missing. Please install the YAML extension; otherwise this plugin will not work');
+		register_activation_hook( __FILE__ , array( &$this, 'plugin_activate' ) );
+		add_action( 'wp_footer', array( &$this, 'export_yaml'));
+	}
+
+	/**
+	 * activate hook
+	 */
+	public static function plugin_activate() {
+		if ( version_compare( phpversion(), 5.3, '<' ) ) {
+			die( 'The minimum PHP version required for this plugin is 5.3' );
 		}
 
-		add_action( 'wp_footer', array( &$this, 'export_yaml'));
-
+		if (!function_exists('yaml_emit')) {
+			die('`yaml_emit` function missing. Please install the YAML extension; otherwise this plugin will not work');
+		}
 	}
 
 	/**
@@ -99,7 +108,7 @@ class WP_FLATBACKUPS {
 				$attachment_path = get_attached_file( $aid );
 				$attachment_file = basename( $attachment_path);
 				$target_file = $flatdir . DIRECTORY_SEPARATOR . $attachment_file;
-				static::debug ('should ' . $post->post_name . ' have this attachment?: ' . $attachment_file );
+				//static::debug ('should ' . $post->post_name . ' have this attachment?: ' . $attachment_file );
 				if ( !is_file($target_file)) {
 					if (!link( $attachment_path, $target_file )) {
 						static::debug("could not hardlink '$attachment_path' to '$target_file'; trying to copy");
@@ -152,7 +161,7 @@ class WP_FLATBACKUPS {
 				$cout = yaml_emit($c, YAML_UTF8_ENCODING );
 				$cout .= "---\n" . $comment->comment_content;
 
-				static::debug ('Exporting comment #' . $comment->comment_ID. ' to ' . $cfile );
+				//static::debug ('Exporting comment #' . $comment->comment_ID. ' to ' . $cfile );
 				file_put_contents ($cfile, $cout);
 				touch ( $cfile, $c_timestamp );
 			}
@@ -165,7 +174,7 @@ class WP_FLATBACKUPS {
 		$out = static::yaml();
 
 		// write log
-		static::debug ('Exporting #' . $post->ID . ', ' . $post->post_name . ' to ' . $flatfile );
+		//static::debug ('Exporting #' . $post->ID . ', ' . $post->post_name . ' to ' . $flatfile );
 		file_put_contents ($flatfile, $out);
 		touch ( $flatfile, $post_timestamp );
 		return true;
@@ -392,18 +401,6 @@ class WP_FLATBACKUPS {
 		error_log(  __CLASS__ . " => " . $message );
 	}
 
-	/**
-	 * debug log messages, if needed
-	 *
-	public static function debug( $message) {
-		if (is_object($message) || is_array($message))
-			$message = json_encode($message);
-
-		if ( defined('WP_DEBUG') && WP_DEBUG == true )
-			error_log ( __CLASS__ . ' => ' . $message);
-	}
-	*/
-
 	/**
 	 *
 	 */