diff --git a/src/engine/db/handlers/dbContractHandler.java b/src/engine/db/handlers/dbContractHandler.java
index 9354882b..69fde2de 100644
--- a/src/engine/db/handlers/dbContractHandler.java
+++ b/src/engine/db/handlers/dbContractHandler.java
@@ -135,7 +135,7 @@ public class dbContractHandler extends dbHandlerBase {
             preparedStatement.setInt(5, (con.getVendorDialog() != null) ? con.getVendorDialog().getObjectUUID() : 0);
             preparedStatement.setInt(6, con.getIconID());
             preparedStatement.setInt(8, con.getObjectUUID());
-            preparedStatement.setLong(7, con.getAllowedBuildings().toLong());
+            preparedStatement.setLong(7, mbEnums.toLong(con.getAllowedBuildings()));
 
             return (preparedStatement.executeUpdate() > 0);
 
diff --git a/src/engine/devcmd/cmds/SlotNpcCmd.java b/src/engine/devcmd/cmds/SlotNpcCmd.java
index 2ca7d820..e933cd92 100644
--- a/src/engine/devcmd/cmds/SlotNpcCmd.java
+++ b/src/engine/devcmd/cmds/SlotNpcCmd.java
@@ -9,10 +9,11 @@
 
 package engine.devcmd.cmds;
 
-import engine.mbEnums.BuildingGroup;
 import engine.devcmd.AbstractDevCmd;
 import engine.gameManager.ChatManager;
 import engine.gameManager.DbManager;
+import engine.mbEnums;
+import engine.mbEnums.BuildingGroup;
 import engine.objects.*;
 import engine.util.StringUtils;
 import org.pmw.tinylog.Logger;
@@ -112,7 +113,7 @@ public class SlotNpcCmd extends AbstractDevCmd {
             case "ON":
                 contract.getAllowedBuildings().add(buildingGroup);
 
-                if (!DbManager.ContractQueries.updateAllowedBuildings(contract, contract.getAllowedBuildings().toLong())) {
+                if (!DbManager.ContractQueries.updateAllowedBuildings(contract, mbEnums.toLong(contract.getAllowedBuildings()))) {
                     Logger.error("Failed to update Database for Contract Allowed buildings");
                     ChatManager.chatSystemError(pc, "Failed to update Database for Contract Allowed buildings. ");
                     return;
@@ -122,7 +123,7 @@ public class SlotNpcCmd extends AbstractDevCmd {
                 break;
             case "OFF":
                 contract.getAllowedBuildings().remove(buildingGroup);
-                if (!DbManager.ContractQueries.updateAllowedBuildings(contract, contract.getAllowedBuildings().toLong())) {
+                if (!DbManager.ContractQueries.updateAllowedBuildings(contract, mbEnums.toLong(contract.getAllowedBuildings()))) {
                     Logger.error("Failed to update Database for Contract Allowed buildings");
                     ChatManager.chatSystemError(pc, "Failed to update Database for Contract Allowed buildings. ");
                     return;
diff --git a/src/engine/mbEnums.java b/src/engine/mbEnums.java
index e80cd8aa..0358f48a 100644
--- a/src/engine/mbEnums.java
+++ b/src/engine/mbEnums.java
@@ -24,8 +24,6 @@ import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.concurrent.ThreadLocalRandom;
 
-;
-
 /*
  * MagicBane engine enumeration class.
  *
@@ -36,6 +34,14 @@ import java.util.concurrent.ThreadLocalRandom;
 
 public class mbEnums {
 
+    public static <T extends Enum<T>> long toLong(EnumSet<T> enumSet) {
+        long r = 0;
+        for (T value : enumSet) {
+            r |= 1L << value.ordinal();
+        }
+        return r;
+    }
+
     public static <E extends java.lang.Enum<E>> EnumSet<E> fromLong(long bitVector, Class<E> enumClass) {
 
         // Bitvector -> EnumSet without the EnumBitvector dependency
@@ -1582,7 +1588,7 @@ public class mbEnums {
     // It is also used as a bitvector flag in the npc
     // building slot mechanics.
 
-    public enum BuildingGroup implements EnumBitSetHelper<BuildingGroup> {
+    public enum BuildingGroup {
         NONE(0, 0),
         TOL(64f, 64f),
         BARRACK(32f, 64f),
diff --git a/src/engine/objects/Contract.java b/src/engine/objects/Contract.java
index 004f7785..53944489 100644
--- a/src/engine/objects/Contract.java
+++ b/src/engine/objects/Contract.java
@@ -9,7 +9,6 @@
 
 package engine.objects;
 
-import ch.claude_martin.enumbitset.EnumBitSet;
 import engine.gameManager.DbManager;
 import engine.mbEnums;
 import org.pmw.tinylog.Logger;
@@ -17,6 +16,7 @@ import org.pmw.tinylog.Logger;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.EnumSet;
 
 public class Contract extends AbstractGameObject {
 
@@ -36,7 +36,7 @@ public class Contract extends AbstractGameObject {
     private ArrayList<Integer> npcModSuffixTable = new ArrayList<>();
     private ArrayList<Byte> itemModTable = new ArrayList<>();
     private ArrayList<Item> sellInventory = new ArrayList<>();
-    private EnumBitSet<mbEnums.BuildingGroup> allowedBuildings;
+    private EnumSet<mbEnums.BuildingGroup> allowedBuildings;
     private ArrayList<Integer> buyItemType = new ArrayList<>();
     private ArrayList<Integer> buySkillToken = new ArrayList<>();
     private ArrayList<Integer> buyUnknownToken = new ArrayList<>();
@@ -85,7 +85,7 @@ public class Contract extends AbstractGameObject {
         this.vendorDialog = VendorDialog.getVendorDialog(rs.getInt("dialogID"));
         this.iconID = rs.getInt("iconID");
         this.vendorID = rs.getInt("vendorID");
-        this.allowedBuildings = EnumBitSet.asEnumBitSet(rs.getLong("allowedBuildingTypeID"), mbEnums.BuildingGroup.class);
+        this.allowedBuildings = mbEnums.fromLong(rs.getLong("allowedBuildingTypeID"), mbEnums.BuildingGroup.class);
         this.equipmentSet = rs.getInt("equipSetID");
         this.inventorySet = rs.getInt("inventorySet");
 
@@ -220,7 +220,7 @@ public class Contract extends AbstractGameObject {
         DbManager.ContractQueries.updateDatabase(this);
     }
 
-    public EnumBitSet<mbEnums.BuildingGroup> getAllowedBuildings() {
+    public EnumSet<mbEnums.BuildingGroup> getAllowedBuildings() {
         return allowedBuildings;
     }
 
@@ -251,7 +251,7 @@ public class Contract extends AbstractGameObject {
             return false;
 
         // Binary match
-        return (building.getBlueprint().getBuildingGroup().elementOf(this.allowedBuildings));
+        return (this.allowedBuildings.contains(building.getBlueprint().getBuildingGroup()));
     }
 
     public int getEquipmentSet() {