diff --git a/core/_bootstrap.inc.php b/core/_bootstrap.inc.php
index 5659665c..4ee5fda6 100644
--- a/core/_bootstrap.inc.php
+++ b/core/_bootstrap.inc.php
@@ -4,6 +4,8 @@
  * actually do anything as far as the app is concerned
  */
 
+global $config, $database, $user, $page;
+
 require_once "core/sys_config.inc.php";
 require_once "core/util.inc.php";
 require_once "lib/context.php";
@@ -23,6 +25,8 @@ foreach($files as $filename) {
 		require_once $filename;
 	}
 }
+unset($files);
+unset($filename);
 ctx_log_endok();
 
 // connect to the database
@@ -36,6 +40,7 @@ ctx_log_start("Loading themelets");
 foreach(_get_themelet_files(get_theme()) as $themelet) {
 	require_once $themelet;
 }
+unset($themelet);
 $page = class_exists("CustomPage") ? new CustomPage() : new Page();
 ctx_log_endok();
 
diff --git a/core/imageboard.pack.php b/core/imageboard.pack.php
index a88461bb..f4153f9a 100644
--- a/core/imageboard.pack.php
+++ b/core/imageboard.pack.php
@@ -23,7 +23,6 @@
 * Classes                                                                   *
 \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-$tag_n = 0; // temp hack
 $_flexihash = null;
 $_fh_last_opts = null;
 $order_sql = null; // this feels ugly
@@ -40,6 +39,8 @@ require_once "lib/flexihash.php";
  * other supported upload type.
  */
 class Image {
+	private static $tag_n = 0; // temp hack
+
 	/** @var null|int */
 	public $id = null;
 
@@ -967,13 +968,10 @@ class Image {
 		$sql = "0";
 		$terms = array();
 		foreach($tag_querylets as $tq) {
-			global $tag_n;
 			$sign = $tq->positive ? "+" : "-";
-			//$sql .= " $sign (tag LIKE :tag$tag_n)";
-			$sql .= ' '.$sign.' (tag LIKE :tag'.$tag_n.')';
-			//$terms["tag$tag_n"] = $tq->tag;
-			$terms['tag'.$tag_n] = $tq->tag;
-			$tag_n++;
+			$sql .= ' '.$sign.' (tag LIKE :tag'.Image::$tag_n.')';
+			$terms['tag'.Image::$tag_n] = $tq->tag;
+			Image::$tag_n++;
 
 			if($sign === "+") $positive_tag_count++;
 			else $negative_tag_count++;
@@ -1084,7 +1082,7 @@ class Image {
 				WHERE 1=0
 			");
 		}
-		$tag_n = 0;
+		Image::$tag_n = 0;
 		return $query;
 	}
 }
diff --git a/core/userclass.class.php b/core/userclass.class.php
index 45ddb1fe..68d2c097 100644
--- a/core/userclass.class.php
+++ b/core/userclass.class.php
@@ -2,6 +2,7 @@
 /**
  * @global UserClass[] $_user_classes
  */
+global $_user_classes;
 $_user_classes = array();
 
 /**
diff --git a/core/util.inc.php b/core/util.inc.php
index ac2ef5a5..e9a7bf5b 100644
--- a/core/util.inc.php
+++ b/core/util.inc.php
@@ -1052,7 +1052,6 @@ function findHeader ($headers, $name) {
 	return $header;
 }
 
-$_included = array();
 /**
  * Get the active contents of a .php file
  *
@@ -1060,13 +1059,13 @@ $_included = array();
  * @return string|null
  */
 function manual_include($fname) {
-	global $_included;
+	static $included = array();
 
 	if(!file_exists($fname)) return null;
 
-	if(in_array($fname, $_included)) return null;
+	if(in_array($fname, $included)) return null;
 
-	$_included[] = $fname;
+	$included[] = $fname;
 
 	print "$fname\n";
 
@@ -1380,6 +1379,7 @@ function path_to_tags($path) {
 \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /** @private */
+global $_event_listeners;
 $_event_listeners = array();
 
 /**
@@ -1401,6 +1401,7 @@ function add_event_listener(Extension $extension, $pos=50, $events=array()) {
 }
 
 /** @private */
+global $_event_count;
 $_event_count = 0;
 
 /**
diff --git a/tests/router.php b/tests/router.php
index e42dfaa5..6c00377b 100644
--- a/tests/router.php
+++ b/tests/router.php
@@ -9,6 +9,7 @@ if(preg_match('/\/_(images|thumbs)\/([0-9a-f]{32}).*$/', $_SERVER["REQUEST_URI"]
 	print(file_get_contents(warehouse_path($matches[1], $matches[2])));
 	return true;
 }
+unset($matches);
 
 // use the default handler (serve static files, interpret php files)
 if(preg_match('/\.(?:png|jpg|jpeg|gif|css|js|php)(\?.*)?$/', $_SERVER["REQUEST_URI"])) {