diff --git a/src/d_clisrv.c b/src/d_clisrv.c
index 6b8c107b5..3a7626ef5 100644
--- a/src/d_clisrv.c
+++ b/src/d_clisrv.c
@@ -2484,7 +2484,13 @@ static boolean CL_ServerConnectionTicker(const char *tmpsave, tic_t *oldtic, tic
 			F_TitleScreenTicker(true);
 			F_TitleScreenDrawer();
 			CL_DrawConnectionStatus();
+#ifdef HAVE_THREADS
+			I_lock_mutex(&m_menu_mutex);
+#endif
 			M_Drawer(); //Needed for drawing messageboxes on the connection screen
+#ifdef HAVE_THREADS
+			I_unlock_mutex(m_menu_mutex);
+#endif
 			I_UpdateNoVsync(); // page flip or blit buffer
 			if (moviemode)
 				M_SaveFrame();