diff --git a/core/src/io/anuke/mindustry/world/BaseBlock.java b/core/src/io/anuke/mindustry/world/BaseBlock.java
index 9010a45361..9561bf9449 100644
--- a/core/src/io/anuke/mindustry/world/BaseBlock.java
+++ b/core/src/io/anuke/mindustry/world/BaseBlock.java
@@ -44,7 +44,7 @@ public abstract class BaseBlock extends MappableContent{
      * Returns the amount of items this block can accept.
      */
     public int acceptStack(Item item, int amount, Tile tile, Unit source){
-        if(acceptItem(item, tile, tile) && hasItems && source.getTeam() == tile.getTeam()){
+        if(acceptItem(item, tile, tile) && hasItems && (source == null || source.getTeam() == tile.getTeam())){
             return Math.min(getMaximumAccepted(tile, item), amount);
         }else{
             return 0;
diff --git a/core/src/io/anuke/mindustry/world/blocks/storage/CoreBlock.java b/core/src/io/anuke/mindustry/world/blocks/storage/CoreBlock.java
index 656cff1e03..09e3046723 100644
--- a/core/src/io/anuke/mindustry/world/blocks/storage/CoreBlock.java
+++ b/core/src/io/anuke/mindustry/world/blocks/storage/CoreBlock.java
@@ -155,7 +155,7 @@ public class CoreBlock extends StorageBlock{
 
     @Override
     public int acceptStack(Item item, int amount, Tile tile, Unit source){
-        if(acceptItem(item, tile, tile) && hasItems && source.getTeam() == tile.getTeam()){
+        if(acceptItem(item, tile, tile) && hasItems && (source == null || source.getTeam() == tile.getTeam())){
             return Math.min(itemCapacity - tile.entity.items.get(item), amount);
         }else{
             return 0;