diff --git a/lib/classes/class-utility.php b/lib/classes/class-utility.php
index fe037e9be..596af8b97 100644
--- a/lib/classes/class-utility.php
+++ b/lib/classes/class-utility.php
@@ -576,7 +576,12 @@ public static function can_delete_attachment($attachment_id, $args){
         ){
           // checks whether it's WP 5.3 and 'intermediate_image_sizes_advanced' is passed.
           // To be sure that we don't delete full size image before thumbnails are generated.
-          if(is_wp_version_compatible('5.3-RC4-46673') && !in_array($attachment_id, self::$can_delete_attachment)){
+          if(
+            wp_attachment_is_image($attachment_id) &&
+            function_exists('is_wp_version_compatible') && 
+            is_wp_version_compatible('5.3-RC4-46673') && 
+            !in_array($attachment_id, self::$can_delete_attachment)
+          ){
             return false;
           }
           return true;
diff --git a/readme.txt b/readme.txt
index 7b011128c..bbaf97ea3 100644
--- a/readme.txt
+++ b/readme.txt
@@ -4,7 +4,7 @@ Donate link: https://www.usabilitydynamics.com
 Tags: google, google cloud, google cloud storage, cdn, uploads, media, stateless, backup
 License: GPLv2 or later
 Requires PHP: 5.5
-Requires at least: 4.0
+Requires at least: 4.7.0
 Tested up to: 5.3
 Stable tag: 2.3.1