diff --git a/src/engine/objects/Warehouse.java b/src/engine/objects/Warehouse.java
index 0f30940d..2b0576ad 100644
--- a/src/engine/objects/Warehouse.java
+++ b/src/engine/objects/Warehouse.java
@@ -640,4 +640,16 @@ public class Warehouse {
         return warehouse.locked.contains(resourceType);
     }
 
+    public static HashMap<mbEnums.ResourceType, Integer> calcOverflow(Warehouse warehouse, HashMap<mbEnums.ResourceType, Integer> cost_map) {
+
+        HashMap<mbEnums.ResourceType, Integer> overflowMap = new HashMap<>();
+
+        for (mbEnums.ResourceType resourceType : cost_map.keySet()) {
+            int debit = warehouse.resources.get(resourceType) - cost_map.get(resourceType);
+            if (debit < 0)
+                overflowMap.put(resourceType, debit);
+        }
+
+        return overflowMap;
+    }
 }
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