diff --git a/lutin/z_system/lutinSystem_Linux_X11.py b/lutin/z_system/lutinSystem_Linux_X11.py
index c623d87..d89b918 100644
--- a/lutin/z_system/lutinSystem_Linux_X11.py
+++ b/lutin/z_system/lutinSystem_Linux_X11.py
@@ -22,6 +22,8 @@ class System(system.System):
 		self.set_valid(True)
 		# no check needed ==> just add this:
 		self.add_depend(['c'])
+		self.add_flag('link-lib', 'Xv')
+		self.add_flag('link-lib', 'Xt')
 		self.add_flag('link-lib', 'X11')
 		if env.get_isolate_system() == True:
 			self.add_header_file([