diff --git a/lib/class-wp-rest-url-details-controller.php b/lib/class-wp-rest-url-details-controller.php
index ee7c1b23a05c7..6a3ef0ebe6943 100644
--- a/lib/class-wp-rest-url-details-controller.php
+++ b/lib/class-wp-rest-url-details-controller.php
@@ -269,7 +269,7 @@ private function get_icon( $html, $url ) {
 
 		// If the icon is a data URL, return it.
 		$parsed_icon = parse_url( $icon );
-		if ( 'data' === $parsed_icon['scheme'] ) {
+		if ( isset( $parsed_icon['schema'] ) && 'data' === $parsed_icon['scheme'] ) {
 			return $icon;
 		}