diff --git a/core/src/mindustry/core/Logic.java b/core/src/mindustry/core/Logic.java
index e4dfc4b997..25c5ed2137 100644
--- a/core/src/mindustry/core/Logic.java
+++ b/core/src/mindustry/core/Logic.java
@@ -156,7 +156,9 @@ public class Logic implements ApplicationListener{
             //TODO maybe make it a separate rule?
             //makes cores go derelict in RTS mode, helps clean things up
             if(e.tile.build instanceof CoreBuild core && core.team.isAI() && core.team.rules().rtsAi){
-                core.team.data().makeDerelict(core.x, core.y, state.rules.enemyCoreBuildRadius);
+                Core.app.post(() -> {
+                    core.team.data().makeDerelict(core.x, core.y, state.rules.enemyCoreBuildRadius);
+                });
             }
         });
 
@@ -175,9 +177,7 @@ public class Logic implements ApplicationListener{
         //listen to core changes; if all cores have been destroyed, set to derelict.
         Events.on(CoreChangeEvent.class, e -> Core.app.post(() -> {
             if(state.rules.cleanupDeadTeams && state.rules.pvp && !e.core.isAdded() && e.core.team != Team.derelict && e.core.team.cores().isEmpty()){
-                Core.app.post(() -> {
-                    e.core.team.data().destroyToDerelict();
-                });
+                e.core.team.data().destroyToDerelict();
             }
         }));
     }
diff --git a/core/src/mindustry/entities/comp/BuildingComp.java b/core/src/mindustry/entities/comp/BuildingComp.java
index ae6b1e2fef..fb13823e30 100644
--- a/core/src/mindustry/entities/comp/BuildingComp.java
+++ b/core/src/mindustry/entities/comp/BuildingComp.java
@@ -1527,10 +1527,16 @@ abstract class BuildingComp implements Posc, Teamc, Healthc, Buildingc, Timerc,
     /** Changes this building's team in a safe manner. */
     public void changeTeam(Team next){
         Team last = this.team;
-        indexer.removeIndex(tile);
+        boolean was = isValid();
+
+        if(was) indexer.removeIndex(tile);
+
         this.team = next;
-        indexer.addIndex(tile);
-        Events.fire(teamChangeEvent.set(last, self()));
+
+        if(was){
+            indexer.addIndex(tile);
+            Events.fire(teamChangeEvent.set(last, self()));
+        }
     }
 
     public boolean canPickup(){