diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index db8a1bdf7d..1d4a6fa24f 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -24,6 +24,7 @@
 #include "group_type.h"
 #include "timetable.h"
 #include "base_consist.h"
+#include "network/network.h"
 #include <list>
 #include <map>
 
@@ -1138,6 +1139,8 @@ struct SpecializedVehicle : public Vehicle {
 	 */
 	inline void UpdateViewport(bool force_update, bool update_delta)
 	{
+		if (_network_dedicated) return;
+
 		/* Explicitly choose method to call to prevent vtable dereference -
 		 * it gives ~3% runtime improvements in games with many vehicles */
 		if (update_delta) ((T *)this)->T::UpdateDeltaXY(this->direction);
diff --git a/src/video/dedicated_v.cpp b/src/video/dedicated_v.cpp
index bfe853e9a0..e55f5621ea 100644
--- a/src/video/dedicated_v.cpp
+++ b/src/video/dedicated_v.cpp
@@ -315,7 +315,6 @@ void VideoDriver_Dedicated::MainLoop()
 			next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 			GameLoop();
-			UpdateWindows();
 		}
 
 		/* Don't sleep when fast forwarding (for desync debugging) */