diff --git a/src/vehicle.cpp b/src/vehicle.cpp
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -900,7 +900,7 @@ static void DoDrawVehicle(const Vehicle 
 	if (v->vehstatus & VS_DEFPAL) pal = (v->vehstatus & VS_CRASHED) ? PALETTE_CRASH : GetVehiclePalette(v);
 
 	/* Check whether the vehicle shall be transparent due to the game state */
-	bool shadowed = (v->vehstatus & VS_SHADOW);
+	bool shadowed = (v->vehstatus & VS_SHADOW) != 0;
 
 	if (v->type == VEH_EFFECT) {
 		/* Check whether the vehicle shall be transparent/invisible due to GUI settings.