diff --git a/src/wp-admin/includes/post.php b/src/wp-admin/includes/post.php
index 77aadb2135..c9738497fa 100644
--- a/src/wp-admin/includes/post.php
+++ b/src/wp-admin/includes/post.php
@@ -2303,7 +2303,7 @@ function the_block_editor_meta_boxes() {
 	<?php the_block_editor_meta_box_post_form_hidden_fields( $post ); ?>
 	</form>
 	<form id="toggle-custom-fields-form" method="post" action="<?php echo esc_attr( admin_url( 'post.php' ) ); ?>">
-		<?php wp_nonce_field( 'toggle-custom-fields' ); ?>
+		<?php wp_nonce_field( 'toggle-custom-fields', 'toggle-custom-fields-nonce' ); ?>
 		<input type="hidden" name="action" value="toggle-custom-fields" />
 	</form>
 	<?php foreach ( $locations as $location ) : ?>
@@ -2435,7 +2435,6 @@ function the_block_editor_meta_box_post_form_hidden_fields( $post ) {
 	$classic_output = ob_get_clean();
 
 	$classic_elements = wp_html_split( $classic_output );
-	$hidden_inputs    = '';
 	foreach ( $classic_elements as $element ) {
 		if ( 0 !== strpos( $element, '<input ' ) ) {
 			continue;
diff --git a/src/wp-admin/post.php b/src/wp-admin/post.php
index c4a0ab17e5..a1113ed35f 100644
--- a/src/wp-admin/post.php
+++ b/src/wp-admin/post.php
@@ -339,7 +339,7 @@ switch ( $action ) {
 		exit;
 
 	case 'toggle-custom-fields':
-		check_admin_referer( 'toggle-custom-fields' );
+		check_admin_referer( 'toggle-custom-fields', 'toggle-custom-fields-nonce' );
 
 		$current_user_id = get_current_user_id();
 		if ( $current_user_id ) {