diff --git a/src/middleware.ts b/src/middleware.ts
index f2c05c6..2964296 100644
--- a/src/middleware.ts
+++ b/src/middleware.ts
@@ -12,11 +12,13 @@ function getSubdomain(req: NextRequest): string | null {
   const portIndex = host.indexOf(":");
   const hostname = portIndex !== -1 ? host.slice(0, portIndex) : host;
 
-  if (hostname === apex || hostname === `www.${apex}`) return null;
+  const reserved = ["www", "coolify", "mail", "accounts", "clerk", "clk", "clk2", "clkmail"];
+
+  if (hostname === apex || reserved.includes(hostname) || hostname === `www.${apex}`) return null;
 
   if (hostname.endsWith(`.${apex}`)) {
     const sub = hostname.slice(0, hostname.length - apex.length - 1);
-    if (sub && sub !== "www") return sub;
+    if (sub && !reserved.includes(sub)) return sub;
   }
 
   return null;