diff --git a/src/servers/app/server/AppServer.h b/src/servers/app/server/AppServer.h
index 7c3df3205e..4f59765e81 100644
--- a/src/servers/app/server/AppServer.h
+++ b/src/servers/app/server/AppServer.h
@@ -14,6 +14,7 @@ class Layer;
 class BMessage;
 class ServerApp;
 class DisplayDriver;
+class BPortLink;
 class CursorManager;
 class BitmapManager;