diff --git a/PluralKit.Bot/Utils/AvatarUtils.cs b/PluralKit.Bot/Utils/AvatarUtils.cs
index 1881d8e4..6fc06c2b 100644
--- a/PluralKit.Bot/Utils/AvatarUtils.cs
+++ b/PluralKit.Bot/Utils/AvatarUtils.cs
@@ -55,7 +55,9 @@ namespace PluralKit.Bot {
         // which in turn makes it more likely to be underneath the size limit!
         private static readonly Regex DiscordCdnUrl = new Regex(@"^https?://(?:cdn\.discordapp\.com|media\.discordapp\.net)/attachments/(\d{17,19})/(\d{17,19})/([^/\\&\?]+)\.(png|jpg|jpeg|webp)(\?.*)?$");
         private static readonly string DiscordMediaUrlReplacement = "https://media.discordapp.net/attachments/$1/$2/$3.$4?width=256&height=256";
-        public static string TryRewriteCdnUrl(string url) =>
-            DiscordCdnUrl.Replace(url, DiscordMediaUrlReplacement);
+        public static string? TryRewriteCdnUrl(string? url)
+        {
+            return url == null ? null : DiscordCdnUrl.Replace(url, DiscordMediaUrlReplacement);
+        }
     }
 }
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