diff --git a/core/src/mindustry/core/NetServer.java b/core/src/mindustry/core/NetServer.java
index 1942e51166..ebd5136139 100644
--- a/core/src/mindustry/core/NetServer.java
+++ b/core/src/mindustry/core/NetServer.java
@@ -23,6 +23,7 @@ import mindustry.net.*;
 import mindustry.net.Administration.*;
 import mindustry.net.Packets.*;
 import mindustry.world.*;
+import mindustry.world.meta.*;
 
 import java.io.*;
 import java.net.*;
@@ -931,19 +932,20 @@ public class NetServer implements ApplicationListener{
         syncStream.reset();
 
         short sent = 0;
-        for(Building entity : Groups.build){
-            if(!entity.block.sync) continue;
-            sent++;
+        for(var team : state.teams.present){
+            for(var build : indexer.getFlagged(team.team, BlockFlag.synced)){
+                sent++;
 
-            dataStream.writeInt(entity.pos());
-            dataStream.writeShort(entity.block.id);
-            entity.writeSync(Writes.get(dataStream));
+                dataStream.writeInt(build.pos());
+                dataStream.writeShort(build.block.id);
+                build.writeSync(Writes.get(dataStream));
 
-            if(syncStream.size() > maxSnapshotSize){
-                dataStream.close();
-                Call.blockSnapshot(sent, syncStream.toByteArray());
-                sent = 0;
-                syncStream.reset();
+                if(syncStream.size() > maxSnapshotSize){
+                    dataStream.close();
+                    Call.blockSnapshot(sent, syncStream.toByteArray());
+                    sent = 0;
+                    syncStream.reset();
+                }
             }
         }
 
diff --git a/core/src/mindustry/world/Block.java b/core/src/mindustry/world/Block.java
index 579f824646..7841f9fbbc 100644
--- a/core/src/mindustry/world/Block.java
+++ b/core/src/mindustry/world/Block.java
@@ -1240,6 +1240,10 @@ public class Block extends UnlockableContent implements Senseable{
             flags = flags.with(BlockFlag.hasFogRadius);
         }
 
+        if(sync){
+            flags = flags.with(BlockFlag.synced);
+        }
+
         //initialize default health based on size
         if(health == -1){
             boolean round = false;
diff --git a/core/src/mindustry/world/blocks/storage/CoreBlock.java b/core/src/mindustry/world/blocks/storage/CoreBlock.java
index 0583fe6b52..65d723da57 100644
--- a/core/src/mindustry/world/blocks/storage/CoreBlock.java
+++ b/core/src/mindustry/world/blocks/storage/CoreBlock.java
@@ -71,6 +71,7 @@ public class CoreBlock extends StorageBlock{
         priority = TargetPriority.core;
         flags = EnumSet.of(BlockFlag.core);
         unitCapModifier = 10;
+        sync = false; //core items are synced elsewhere
         drawDisabled = false;
         canOverdrive = false;
         commandable = true;
diff --git a/core/src/mindustry/world/blocks/storage/StorageBlock.java b/core/src/mindustry/world/blocks/storage/StorageBlock.java
index cb0fc541f1..31dd510f89 100644
--- a/core/src/mindustry/world/blocks/storage/StorageBlock.java
+++ b/core/src/mindustry/world/blocks/storage/StorageBlock.java
@@ -21,6 +21,7 @@ public class StorageBlock extends Block{
         hasItems = true;
         solid = true;
         update = false;
+        sync = true;
         destructible = true;
         separateItemCapacity = true;
         group = BlockGroup.transportation;
diff --git a/core/src/mindustry/world/meta/BlockFlag.java b/core/src/mindustry/world/meta/BlockFlag.java
index 9f6cd57a33..0e36efd5e7 100644
--- a/core/src/mindustry/world/meta/BlockFlag.java
+++ b/core/src/mindustry/world/meta/BlockFlag.java
@@ -31,7 +31,8 @@ public enum BlockFlag{
     unitAssembler,
     hasFogRadius,
     steamVent,
-    blockRepair;
+    blockRepair,
+    synced;
 
     public final static BlockFlag[] all = values();