diff --git a/wp-includes/html-api/class-wp-html-processor.php b/wp-includes/html-api/class-wp-html-processor.php
index 9abc782d0c..cfcd6bdb94 100644
--- a/wp-includes/html-api/class-wp-html-processor.php
+++ b/wp-includes/html-api/class-wp-html-processor.php
@@ -557,6 +557,10 @@ class WP_HTML_Processor extends WP_HTML_Tag_Processor {
 			return false;
 		}
 
+		if ( isset( $query['tag_name'] ) ) {
+			$query['tag_name'] = strtoupper( $query['tag_name'] );
+		}
+
 		$needs_class = ( isset( $query['class_name'] ) && is_string( $query['class_name'] ) )
 			? $query['class_name']
 			: null;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4846ac917c..998689abce 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.8-alpha-59419';
+$wp_version = '6.8-alpha-59422';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.