diff --git a/src/engine/gameManager/SimulationManager.java b/src/engine/gameManager/SimulationManager.java
index fe7ec7e6..a34804a1 100644
--- a/src/engine/gameManager/SimulationManager.java
+++ b/src/engine/gameManager/SimulationManager.java
@@ -201,7 +201,7 @@ public enum SimulationManager {
             city.onEnter();
         }
         for(Mine mine : Mine.getMines()){
-            if(mine != null)
+            if(mine != null && mine.isActive)
                 mine.onEnter();
         }
         _cityPulseTime = System.currentTimeMillis() + CITY_PULSE;
diff --git a/src/engine/workthreads/HalfHourlyJobThread.java b/src/engine/workthreads/HalfHourlyJobThread.java
index 8b878e26..623d1af4 100644
--- a/src/engine/workthreads/HalfHourlyJobThread.java
+++ b/src/engine/workthreads/HalfHourlyJobThread.java
@@ -146,6 +146,11 @@ public class HalfHourlyJobThread implements Runnable {
         mine.lastClaimer = null;
         mine.setActive(false);
         mine.wasClaimed = true;
+        for(Integer id : mine._playerMemory){
+            PlayerCharacter pc = PlayerCharacter.getFromCache(id);
+            if(pc != null)
+                pc.ZergMultiplier = 1.0f;
+        }
         return true;
     }