diff --git a/Delta/Database/Model/Delta.xcdatamodeld/Delta 2.xcdatamodel/contents b/Delta/Database/Model/Delta.xcdatamodeld/Delta 2.xcdatamodel/contents
index 0a25f33..5fe9151 100644
--- a/Delta/Database/Model/Delta.xcdatamodeld/Delta 2.xcdatamodel/contents	
+++ b/Delta/Database/Model/Delta.xcdatamodeld/Delta 2.xcdatamodel/contents	
@@ -96,6 +96,7 @@
                 <entry key="attributeValueClassName" value="GameType"/>
             </userInfo>
         </attribute>
+        <attribute name="identifier" attributeType="String" syncable="YES"/>
         <attribute name="playerIndex" attributeType="Integer 16" defaultValueString="0" usesScalarValueType="NO" syncable="YES"/>
         <uniquenessConstraints>
             <uniquenessConstraint>
@@ -103,6 +104,9 @@
                 <constraint value="gameType"/>
                 <constraint value="playerIndex"/>
             </uniquenessConstraint>
+            <uniquenessConstraint>
+                <constraint value="identifier"/>
+            </uniquenessConstraint>
         </uniquenessConstraints>
     </entity>
     <entity name="SaveState" representedClassName="SaveState" versionHashModifier="quick" syncable="YES">
@@ -133,7 +137,7 @@
         <element name="ControllerSkin" positionX="-387" positionY="90" width="128" height="135"/>
         <element name="Game" positionX="-378" positionY="-54" width="128" height="195"/>
         <element name="GameCollection" positionX="-585" positionY="-27" width="128" height="90"/>
-        <element name="GameControllerInputMapping" positionX="-387" positionY="90" width="128" height="105"/>
+        <element name="GameControllerInputMapping" positionX="-387" positionY="90" width="128" height="120"/>
         <element name="SaveState" positionX="-198" positionY="113" width="128" height="165"/>
     </elements>
 </model>
\ No newline at end of file
diff --git a/Delta/Database/Model/Human/GameControllerInputMapping.swift b/Delta/Database/Model/Human/GameControllerInputMapping.swift
index 0a71b27..03793ab 100644
--- a/Delta/Database/Model/Human/GameControllerInputMapping.swift
+++ b/Delta/Database/Model/Human/GameControllerInputMapping.swift
@@ -9,6 +9,7 @@
 import Foundation
 
 import DeltaCore
+import Harmony
 
 @objc(GameControllerInputMapping)
 public class GameControllerInputMapping: _GameControllerInputMapping
@@ -24,6 +25,13 @@ public class GameControllerInputMapping: _GameControllerInputMapping
         
         self.inputMapping = inputMapping
     }
+    
+    public override func awakeFromInsert()
+    {
+        super.awakeFromInsert()
+        
+        self.identifier = UUID().uuidString
+    }
 }
 
 extension GameControllerInputMapping
@@ -75,3 +83,17 @@ extension GameControllerInputMapping: GameControllerInputMappingProtocol
         self.inputMapping.set(input, forControllerInput: controllerInput)
     }
 }
+
+extension GameControllerInputMapping: Syncable
+{
+    public static var syncablePrimaryKey: AnyKeyPath {
+        return \GameControllerInputMapping.identifier
+    }
+
+    public var syncableKeys: Set<AnyKeyPath> {
+        return [\GameControllerInputMapping.deltaCoreInputMapping,
+                \GameControllerInputMapping.gameControllerInputType,
+                \GameControllerInputMapping.gameType,
+                \GameControllerInputMapping.playerIndex]
+    }
+}
diff --git a/Delta/Database/Model/Machine/_GameControllerInputMapping.swift b/Delta/Database/Model/Machine/_GameControllerInputMapping.swift
index cc28acb..7f6d159 100644
--- a/Delta/Database/Model/Machine/_GameControllerInputMapping.swift
+++ b/Delta/Database/Model/Machine/_GameControllerInputMapping.swift
@@ -20,6 +20,8 @@ public class _GameControllerInputMapping: NSManagedObject
 
     @NSManaged public var gameType: GameType
 
+    @NSManaged public var identifier: String
+
     @NSManaged public var playerIndex: Int16
 
     // MARK: - Relationships
diff --git a/External/Harmony b/External/Harmony
index ee45cd9..2c8aed1 160000
--- a/External/Harmony
+++ b/External/Harmony
@@ -1 +1 @@
-Subproject commit ee45cd9ff3ff6c50c29e85cd466c4031108c3fde
+Subproject commit 2c8aed14f6287e45eb3c32017de590ec4323e64f