diff --git a/mdl/m_socket_class.pas b/mdl/m_socket_class.pas
index d5a26c2..d61eb52 100644
--- a/mdl/m_socket_class.pas
+++ b/mdl/m_socket_class.pas
@@ -5,6 +5,9 @@ Unit m_Socket_Class;
 Interface
 
 Uses
+  {$IFDEF OS2}
+    WinSock,
+  {$ENDIF}
   {$IFDEF WIN32}
     Windows,
     Winsock2,