diff --git a/ext/tag_categories/main.php b/ext/tag_categories/main.php
index 285a18e8..80f62e88 100644
--- a/ext/tag_categories/main.php
+++ b/ext/tag_categories/main.php
@@ -51,7 +51,7 @@ class TagCategories extends Extension {
 	public function onSearchTermParse(SearchTermParseEvent $event) {
 		$matches = array();
 
-		if(preg_match("/^(.+)tags([:]?<|[:]?>|[:]?<=|[:]?>=|[:|=])([0-9]+)$/", $event->term, $matches)) {
+		if(preg_match("/^(.+)tags([:]?<|[:]?>|[:]?<=|[:]?>=|[:|=])([0-9]+)$/i", $event->term, $matches)) {
 			global $database;
 			$type = $matches[1];
 			$cmp = ltrim($matches[2], ":") ?: "=";
@@ -59,15 +59,15 @@ class TagCategories extends Extension {
 
 			$types = $database->get_col('SELECT category FROM image_tag_categories');
 			if(in_array($type, $types)) {
-				$event->add_querylet(new Querylet("images.id IN (
-													SELECT * FROM (
-														SELECT it.image_id
-														FROM image_tags it
-														LEFT JOIN tags t ON it.tag_id = t.id
-														GROUP BY image_id
-														HAVING SUM(CASE WHEN t.tag LIKE '$type:%' THEN 1 ELSE 0 END) $cmp $count
-													) AS subquery
-												   )"));
+				$event->add_querylet(
+					new Querylet("EXISTS (
+					    SELECT 1
+					    FROM image_tags it
+					    LEFT JOIN tags t ON it.tag_id = t.id
+					    WHERE images.id = it.image_id
+					    GROUP BY image_id
+					    HAVING SUM(CASE WHEN t.tag LIKE '$type:%' THEN 1 ELSE 0 END) $cmp $count
+					)"));
 			}
 		}
 	}