diff --git a/src/engine/objects/Warehouse.java b/src/engine/objects/Warehouse.java
index 02ea37a1..0bcdce7c 100644
--- a/src/engine/objects/Warehouse.java
+++ b/src/engine/objects/Warehouse.java
@@ -645,7 +645,9 @@ public class Warehouse {
 
             int debit = warehouse.resources.get(resourceType) - cost_map.get(resourceType);
 
-            if (debit < 0)
+            // Locked resources are always unavailable
+
+            if (debit < 0 || warehouse.locked.contains(resourceType))
                 overflowMap.put(resourceType, debit);
         }