diff --git a/src/main/java/de/ellpeck/actuallyadditions/mod/inventory/slot/SlotFilter.java b/src/main/java/de/ellpeck/actuallyadditions/mod/inventory/slot/SlotFilter.java
index 4cbb4521f..4bc3bcfd8 100644
--- a/src/main/java/de/ellpeck/actuallyadditions/mod/inventory/slot/SlotFilter.java
+++ b/src/main/java/de/ellpeck/actuallyadditions/mod/inventory/slot/SlotFilter.java
@@ -45,7 +45,7 @@ public class SlotFilter extends Slot{
             }
         }
 
-        return null;
+        return StackUtil.getNull();
     }
 
     @Override