diff --git a/zmq.pas b/zmq.pas
index a5a1b65..018b9ad 100644
--- a/zmq.pas
+++ b/zmq.pas
@@ -382,7 +382,11 @@ function zmq_socket_monitor( s: Pointer; addr: PAnsiChar; events: Integer ): Int
 type
   pollitem_t = record
     socket: Pointer;
-    fd: Integer; // TSocket???
+    {$if Defined(UNIX) or Defined(WIN64)}
+    fd: QWord; // TSocket???
+    {$else}
+    fd: Cardinal;
+    {$endif}
     events: Word;
     revents: Word;
   end;