diff --git a/src/Umbraco.Core/Persistence/Caching/InMemoryCacheProvider.cs b/src/Umbraco.Core/Persistence/Caching/InMemoryCacheProvider.cs
index 5544c74494..7572dcd5c5 100644
--- a/src/Umbraco.Core/Persistence/Caching/InMemoryCacheProvider.cs
+++ b/src/Umbraco.Core/Persistence/Caching/InMemoryCacheProvider.cs
@@ -37,7 +37,10 @@ namespace Umbraco.Core.Persistence.Caching
             var containsKey = _cache.ContainsKey(compositeKey);
             if (containsKey)
             {
-                return _cache[compositeKey];
+                var result = _cache[compositeKey];
+
+                //IMPORTANT: we must clone to resolve, see: http://issues.umbraco.org/issue/U4-4259
+                return (IEntity)result.DeepClone();
             }
 
             return null;
@@ -56,7 +59,12 @@ namespace Umbraco.Core.Persistence.Caching
                             into key
                             let containsKey = _cache.ContainsKey(key)
                             where containsKey
-                            select _cache[key]).ToList();
+                            select _cache[key]
+                            into result 
+                            //don't return null objects
+                            where result != null
+                            //IMPORTANT: we must clone to resolve, see: http://issues.umbraco.org/issue/U4-4259
+                            select (IEntity)result.DeepClone()).ToList();
             return list;
         }
 
@@ -67,7 +75,14 @@ namespace Umbraco.Core.Persistence.Caching
         /// <returns></returns>
         public IEnumerable<IEntity> GetAllByType(Type type)
         {
-            var list = _cache.Keys.Where(key => key.Contains(type.Name)).Select(key => _cache[key]).ToList();
+            var list = _cache.Keys
+                .Where(key => key.Contains(type.Name))
+                .Select(key => _cache[key])
+                //don't return null objects
+                .Where(result => result != null)
+                //IMPORTANT: we must clone to resolve, see: http://issues.umbraco.org/issue/U4-4259
+                .Select(result => (IEntity)result.DeepClone())
+                .ToList();
             return list;
         }
 
@@ -78,6 +93,9 @@ namespace Umbraco.Core.Persistence.Caching
         /// <param name="entity"></param>
         public void Save(Type type, IEntity entity)
         {
+            //IMPORTANT: we must clone to store, see: http://issues.umbraco.org/issue/U4-4259
+            entity = (IEntity)entity.DeepClone();
+
             _cache.AddOrUpdate(GetCompositeId(type, entity.Id), entity, (x, y) => entity);
         }
 
diff --git a/src/Umbraco.Core/Persistence/Caching/RuntimeCacheProvider.cs b/src/Umbraco.Core/Persistence/Caching/RuntimeCacheProvider.cs
index ff6db47860..c2ca53a240 100644
--- a/src/Umbraco.Core/Persistence/Caching/RuntimeCacheProvider.cs
+++ b/src/Umbraco.Core/Persistence/Caching/RuntimeCacheProvider.cs
@@ -67,8 +67,11 @@ namespace Umbraco.Core.Persistence.Caching
             {
                 //ensure the key doesn't exist anymore in the tracker
                 _keyTracker.Remove(key);
+                return null;
             }
-            return result;
+
+            //IMPORTANT: we must clone to resolve, see: http://issues.umbraco.org/issue/U4-4259
+            return (IEntity)result.DeepClone();
         }
 
         public IEnumerable<IEntity> GetByIds(Type type, List<Guid> ids)
@@ -88,7 +91,8 @@ namespace Umbraco.Core.Persistence.Caching
                 }
                 else
                 {
-                    collection.Add(result);
+                    //IMPORTANT: we must clone to resolve, see: http://issues.umbraco.org/issue/U4-4259
+                    collection.Add((IEntity)result.DeepClone());
                 }
             }
             return collection;
@@ -113,7 +117,8 @@ namespace Umbraco.Core.Persistence.Caching
                     }
                     else
                     {
-                        collection.Add(result);
+                        //IMPORTANT: we must clone to resolve, see: http://issues.umbraco.org/issue/U4-4259
+                        collection.Add((IEntity)result.DeepClone());
                     }
                 }
             }
@@ -122,6 +127,9 @@ namespace Umbraco.Core.Persistence.Caching
 
         public void Save(Type type, IEntity entity)
         {
+            //IMPORTANT: we must clone to store, see: http://issues.umbraco.org/issue/U4-4259
+            entity = (IEntity)entity.DeepClone();
+
             var key = GetCompositeId(type, entity.Id);
             
             _keyTracker.TryAdd(key);