diff --git a/core/src/mindustry/input/Placement.java b/core/src/mindustry/input/Placement.java
index 62ae4932b0..47fefecdcb 100644
--- a/core/src/mindustry/input/Placement.java
+++ b/core/src/mindustry/input/Placement.java
@@ -55,11 +55,12 @@ public class Placement{
     }
 
     public static Seq<Point2> upgradeLine(int startX, int startY, int endX, int endY){
+        closed.clear();
         Pools.freeAll(points);
         points.clear();
         var build = world.build(startX, startY);
         points.add(Pools.obtain(Point2.class, Point2::new).set(startX, startY));
-        while(build instanceof ChainedBuilding chain && (build.tile.x != endX || build.tile.y != endY)){
+        while(build instanceof ChainedBuilding chain && (build.tile.x != endX || build.tile.y != endY) && closed.add(build.id)){
             if(chain.next() == null) return pathfindLine(true, startX, startY, endX, endY);
             build = chain.next();
             points.add(Pools.obtain(Point2.class, Point2::new).set(build.tile.x, build.tile.y));