diff --git a/src/engine/gameManager/ForgeManager.java b/src/engine/gameManager/ForgeManager.java
index 32c39b04..99d1b082 100644
--- a/src/engine/gameManager/ForgeManager.java
+++ b/src/engine/gameManager/ForgeManager.java
@@ -18,6 +18,7 @@ import org.pmw.tinylog.Logger;
 import java.util.HashMap;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.DelayQueue;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 public enum ForgeManager implements Runnable {
@@ -149,7 +150,7 @@ public enum ForgeManager implements Runnable {
         float rollingDuration;
 
         rollingDuration = workOrder.vendor.getBuilding().getRank() * -5L + 40;
-        rollingDuration *= 60000;
+        rollingDuration = TimeUnit.MINUTES.toMillis((long) rollingDuration);
         rollingDuration *= Float.parseFloat(ConfigManager.MB_PRODUCTION_RATE.getValue());
 
         ItemTemplate template = ItemTemplate.templates.get(workOrder.templateID);