diff --git a/src/redmine-net-api/Extensions/CollectionExtensions.cs b/src/redmine-net-api/Extensions/CollectionExtensions.cs
index 5a14bfe3..60703635 100755
--- a/src/redmine-net-api/Extensions/CollectionExtensions.cs
+++ b/src/redmine-net-api/Extensions/CollectionExtensions.cs
@@ -17,6 +17,7 @@ limitations under the License.
 using System;
 using System.Collections.Generic;
 using System.Text;
+using Redmine.Net.Api.Types;
 
 namespace Redmine.Net.Api.Extensions
 {
@@ -30,8 +31,9 @@ public static class CollectionExtensions
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="listToClone">The list to clone.</param>
+        /// <param name="resetId"></param>
         /// <returns></returns>
-        public static IList<T> Clone<T>(this IList<T> listToClone) where T : ICloneable
+        public static IList<T> Clone<T>(this IList<T> listToClone, bool resetId) where T : ICloneable<T>
         {
             if (listToClone == null)
             {
@@ -43,7 +45,7 @@ public static IList<T> Clone<T>(this IList<T> listToClone) where T : ICloneable
             for (var index = 0; index < listToClone.Count; index++)
             {
                 var item = listToClone[index];
-                clonedList.Add((T) item.Clone());
+                clonedList.Add(item.Clone(resetId));
             }
 
             return clonedList;
diff --git a/src/redmine-net-api/ICloneableOfT.cs b/src/redmine-net-api/ICloneableOfT.cs
new file mode 100644
index 00000000..dd58fde2
--- /dev/null
+++ b/src/redmine-net-api/ICloneableOfT.cs
@@ -0,0 +1,14 @@
+namespace Redmine.Net.Api;
+
+/// <summary>
+/// 
+/// </summary>
+/// <typeparam name="T"></typeparam>
+public interface ICloneable<out T>
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    internal T Clone(bool resetId);
+}
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/Attachment.cs b/src/redmine-net-api/Types/Attachment.cs
index f831d647..bc394f77 100644
--- a/src/redmine-net-api/Types/Attachment.cs
+++ b/src/redmine-net-api/Types/Attachment.cs
@@ -33,6 +33,7 @@ namespace Redmine.Net.Api.Types
     [XmlRoot(RedmineKeys.ATTACHMENT)]
     public sealed class Attachment : 
         Identifiable<Attachment>
+        , ICloneable<Attachment>
     {
         #region Properties
         /// <summary>
@@ -266,5 +267,39 @@ public override int GetHashCode()
 Author={Author}, 
 CreatedOn={CreatedOn?.ToString("u", CultureInfo.InvariantCulture)}]";
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public new Attachment Clone(bool resetId)
+        {
+            if (resetId)
+            {
+                return new Attachment
+                {
+                    FileName = FileName,
+                    FileSize = FileSize,
+                    ContentType = ContentType,
+                    Description = Description,
+                    ContentUrl = ContentUrl,
+                    ThumbnailUrl = ThumbnailUrl,
+                    Author = Author?.Clone(false),
+                    CreatedOn = CreatedOn
+                };
+            }
+            
+            return new Attachment
+            {
+                Id = Id,
+                FileName = FileName,
+                FileSize = FileSize,
+                ContentType = ContentType,
+                Description = Description,
+                ContentUrl = ContentUrl,
+                ThumbnailUrl = ThumbnailUrl,
+                Author = Author?.Clone(true),
+                CreatedOn = CreatedOn
+            };
+        }
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/ChangeSet.cs b/src/redmine-net-api/Types/ChangeSet.cs
index bf07bc83..dae77667 100644
--- a/src/redmine-net-api/Types/ChangeSet.cs
+++ b/src/redmine-net-api/Types/ChangeSet.cs
@@ -33,6 +33,7 @@ namespace Redmine.Net.Api.Types
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     [XmlRoot(RedmineKeys.CHANGE_SET)]
     public sealed class ChangeSet : IXmlSerializable, IJsonSerializable, IEquatable<ChangeSet>
+    ,ICloneable<ChangeSet>
     {
         #region Properties
         /// <summary>
@@ -157,6 +158,23 @@ public bool Equals(ChangeSet other)
                 && CommittedOn == other.CommittedOn;
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="resetId"></param>
+        /// <returns></returns>
+        /// <exception cref="NotImplementedException"></exception>
+        public ChangeSet Clone(bool resetId)
+        {
+            return new ChangeSet()
+            {
+                User = User,
+                Comments = Comments,
+                Revision = Revision,
+                CommittedOn = CommittedOn,
+            };
+        }
+
         /// <summary>
         /// 
         /// </summary>
diff --git a/src/redmine-net-api/Types/CustomFieldValue.cs b/src/redmine-net-api/Types/CustomFieldValue.cs
index 5cc91ae5..592bb4f4 100644
--- a/src/redmine-net-api/Types/CustomFieldValue.cs
+++ b/src/redmine-net-api/Types/CustomFieldValue.cs
@@ -34,6 +34,7 @@ public class CustomFieldValue :
         IXmlSerializable
         ,IJsonSerializable
         ,IEquatable<CustomFieldValue>
+        ,ICloneable<CustomFieldValue>
     {
         /// <summary>
         /// 
@@ -205,10 +206,9 @@ public override int GetHashCode()
         /// 
         /// </summary>
         /// <returns></returns>
-        public object Clone()
+        public CustomFieldValue Clone(bool resetId)
         {
-            var customFieldValue = new CustomFieldValue {Info = Info};
-            return customFieldValue;
+            return new CustomFieldValue { Info = Info };
         }
 
         #endregion
diff --git a/src/redmine-net-api/Types/Detail.cs b/src/redmine-net-api/Types/Detail.cs
index 35e3fcc4..a17a0d9a 100644
--- a/src/redmine-net-api/Types/Detail.cs
+++ b/src/redmine-net-api/Types/Detail.cs
@@ -34,6 +34,7 @@ public sealed class Detail :
         IXmlSerializable
         ,IJsonSerializable
         ,IEquatable<Detail>
+        ,ICloneable<Detail>
     {
         /// <summary>
         /// 
@@ -182,6 +183,16 @@ public bool Equals(Detail other)
                 && string.Equals(NewValue, other.NewValue, StringComparison.OrdinalIgnoreCase);
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        /// <exception cref="NotImplementedException"></exception>
+        public Detail Clone(bool resetId)
+        {
+            return new Detail(Name, Property, OldValue, NewValue);
+        }
+
         /// <summary>
         /// 
         /// </summary>
diff --git a/src/redmine-net-api/Types/Identifiable.cs b/src/redmine-net-api/Types/Identifiable.cs
index 24124e0c..e5123673 100644
--- a/src/redmine-net-api/Types/Identifiable.cs
+++ b/src/redmine-net-api/Types/Identifiable.cs
@@ -33,6 +33,7 @@ namespace Redmine.Net.Api.Types
     /// <typeparam name="T"></typeparam>
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     public abstract class Identifiable<T> : IXmlSerializable, IJsonSerializable, IEquatable<T>
+        , ICloneable<Identifiable<T>> 
         where T : Identifiable<T>
     {
         #region Properties
@@ -158,5 +159,13 @@ public override int GetHashCode()
         /// <returns></returns>
         private string DebuggerDisplay => $"Id={Id.ToString(CultureInfo.InvariantCulture)}";
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public virtual Identifiable<T> Clone(bool resetId)
+        {
+            throw new NotImplementedException();
+        }
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/IdentifiableName.cs b/src/redmine-net-api/Types/IdentifiableName.cs
index d9deafde..b4717d4e 100644
--- a/src/redmine-net-api/Types/IdentifiableName.cs
+++ b/src/redmine-net-api/Types/IdentifiableName.cs
@@ -29,6 +29,7 @@ namespace Redmine.Net.Api.Types
     /// </summary>
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     public class IdentifiableName : Identifiable<IdentifiableName>
+        , ICloneable<IdentifiableName>
     {
         /// <summary>
         /// 
@@ -224,5 +225,18 @@ public override int GetHashCode()
         /// </summary>
         /// <returns></returns>
         private string DebuggerDisplay => $"[{nameof(IdentifiableName)}: {base.ToString()}, Name={Name}]";
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public new IdentifiableName Clone(bool resetId)
+        {
+            return new IdentifiableName
+            {
+                Id = Id,
+                Name = Name
+            };
+        }
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/Issue.cs b/src/redmine-net-api/Types/Issue.cs
index 8559b3ce..9e97f373 100644
--- a/src/redmine-net-api/Types/Issue.cs
+++ b/src/redmine-net-api/Types/Issue.cs
@@ -40,6 +40,7 @@ namespace Redmine.Net.Api.Types
     [XmlRoot(RedmineKeys.ISSUE)]
     public sealed class Issue : 
         Identifiable<Issue>
+        ,ICloneable<Issue>
     {
         #region Properties
         /// <summary>
@@ -588,36 +589,51 @@ public override int GetHashCode()
         }
         #endregion
 
-        #region Implementation of IClonable
+        #region Implementation of IClonable<T>
         /// <summary>
         /// 
         /// </summary>
         /// <returns></returns>
-        public object Clone()
+        public new Issue Clone(bool resetId)
         {
             var issue = new Issue
             {
-                AssignedTo = AssignedTo,
-                Author = Author,
-                Category = Category,
-                CustomFields = CustomFields,
+                Project = Project?.Clone(false),
+                Tracker = Tracker?.Clone(false),
+                Status = Status?.Clone(false),
+                Priority = Priority?.Clone(false),
+                Author = Author?.Clone(false),
+                Category = Category?.Clone(false),
+                Subject = Subject,
                 Description = Description,
-                DoneRatio = DoneRatio,
+                StartDate = StartDate,
                 DueDate = DueDate,
-                SpentHours = SpentHours,
+                DoneRatio = DoneRatio,
+                IsPrivate = IsPrivate,
                 EstimatedHours = EstimatedHours,
-                Priority = Priority,
-                StartDate = StartDate,
-                Status = Status,
-                Subject = Subject,
-                Tracker = Tracker,
-                Project = Project,
-                FixedVersion = FixedVersion,
+                TotalEstimatedHours = TotalEstimatedHours,
+                SpentHours = SpentHours,
+                TotalSpentHours = TotalSpentHours,
+                AssignedTo = AssignedTo?.Clone(false),
+                FixedVersion = FixedVersion?.Clone(false),
                 Notes = Notes,
-                Watchers = Watchers
+                PrivateNotes = PrivateNotes,
+                CreatedOn = CreatedOn,
+                UpdatedOn = UpdatedOn,
+                ClosedOn = ClosedOn,
+                ParentIssue = ParentIssue?.Clone(false),
+                CustomFields = CustomFields?.Clone(false),
+                Journals = Journals?.Clone(false),
+                Attachments = Attachments?.Clone(false),
+                Relations = Relations?.Clone(false),
+                Children = Children?.Clone(false),
+                Watchers = Watchers?.Clone(false),
+                Uploads = Uploads?.Clone(false),
             };
+
             return issue;
         }
+
         #endregion
 
         /// <summary>
@@ -659,6 +675,5 @@ public IdentifiableName AsParent()
 Children={Children.Dump()}, 
 Uploads={Uploads.Dump()}, 
 Watchers={Watchers.Dump()}]";
-
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/IssueChild.cs b/src/redmine-net-api/Types/IssueChild.cs
index 317aa80f..f92e3fd4 100644
--- a/src/redmine-net-api/Types/IssueChild.cs
+++ b/src/redmine-net-api/Types/IssueChild.cs
@@ -31,6 +31,7 @@ namespace Redmine.Net.Api.Types
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     [XmlRoot(RedmineKeys.ISSUE)]
     public sealed class IssueChild : Identifiable<IssueChild>
+        ,ICloneable<IssueChild>
     {
         #region Properties
         /// <summary>
@@ -173,12 +174,12 @@ public override int GetHashCode()
         /// 
         /// </summary>
         /// <returns></returns>
-        public new IssueChild Clone()
+        public new IssueChild Clone(bool resetId)
         {
             return new IssueChild
             {
                 Id = Id,
-                Tracker = Tracker,
+                Tracker = Tracker?.Clone(false),
                 Subject = Subject
             };
         }
diff --git a/src/redmine-net-api/Types/IssueCustomField.cs b/src/redmine-net-api/Types/IssueCustomField.cs
index 5c570862..31d012cc 100644
--- a/src/redmine-net-api/Types/IssueCustomField.cs
+++ b/src/redmine-net-api/Types/IssueCustomField.cs
@@ -34,6 +34,7 @@ namespace Redmine.Net.Api.Types
     public sealed class IssueCustomField : 
         IdentifiableName
         ,IEquatable<IssueCustomField>
+        ,ICloneable<IssueCustomField>, IValue
     {
         #region Properties
         /// <summary>
@@ -270,16 +271,37 @@ public override int GetHashCode()
         }
         #endregion
 
-        #region Implementation of IClonable
+        #region Implementation of IClonable<IssueCustomField>
         /// <summary>
         /// 
         /// </summary>
         /// <returns></returns>
-        public object Clone()
+        public new IssueCustomField Clone(bool resetId)
         {
-            var issueCustomField = new IssueCustomField { Multiple = Multiple, Values = Values };
-            return issueCustomField;
+            IssueCustomField clone;
+            if (resetId)
+            {
+                clone = new IssueCustomField();
+            }
+            else
+            {
+                clone = new IssueCustomField
+                {
+                    Id = Id,
+                };
+            }
+
+            clone.Name = Name;
+            clone.Multiple = Multiple;
+
+            if (Values != null)
+            {
+                clone.Values = new List<CustomFieldValue>(Values);
+            }
+
+            return clone;
         }
+        
         #endregion
 
         #region Implementation of IValue
diff --git a/src/redmine-net-api/Types/IssueRelation.cs b/src/redmine-net-api/Types/IssueRelation.cs
index 84c9c501..16571f7e 100644
--- a/src/redmine-net-api/Types/IssueRelation.cs
+++ b/src/redmine-net-api/Types/IssueRelation.cs
@@ -34,6 +34,7 @@ namespace Redmine.Net.Api.Types
     [XmlRoot(RedmineKeys.RELATION)]
     public sealed class IssueRelation : 
         Identifiable<IssueRelation>
+        ,ICloneable<IssueRelation>
     {
         #region Properties
         /// <summary>
@@ -284,5 +285,30 @@ public override int GetHashCode()
 Type={Type:G},
 Delay={Delay?.ToString(CultureInfo.InvariantCulture)}]";
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public new IssueRelation Clone(bool resetId)
+        {
+            if (resetId)
+            {
+                return new IssueRelation
+                {
+                    IssueId = IssueId,
+                    IssueToId = IssueToId,
+                    Type = Type,
+                    Delay = Delay
+                };
+            }
+            return new IssueRelation
+            {
+                Id = Id,
+                IssueId = IssueId,
+                IssueToId = IssueToId,
+                Type = Type,
+                Delay = Delay
+            };
+        }
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/Journal.cs b/src/redmine-net-api/Types/Journal.cs
index 6f776b24..325eedbd 100644
--- a/src/redmine-net-api/Types/Journal.cs
+++ b/src/redmine-net-api/Types/Journal.cs
@@ -33,6 +33,7 @@ namespace Redmine.Net.Api.Types
     [XmlRoot(RedmineKeys.JOURNAL)]
     public sealed class Journal : 
         Identifiable<Journal>
+        ,ICloneable<Journal>
     {
         #region Properties
         /// <summary>
@@ -253,5 +254,32 @@ public override int GetHashCode()
         /// <returns></returns>
         private string DebuggerDisplay => $"[{nameof(Journal)}: {ToString()}, User={User}, Notes={Notes}, CreatedOn={CreatedOn?.ToString("u", CultureInfo.InvariantCulture)}, Details={Details.Dump()}]";
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public new Journal Clone(bool resetId)
+        {
+            if (resetId)
+            {
+                return new Journal
+                {
+                    User = User?.Clone(false),
+                    Notes = Notes,
+                    CreatedOn = CreatedOn,
+                    PrivateNotes = PrivateNotes,
+                    Details = Details?.Clone(false)
+                };
+            }
+            return new Journal
+            {
+                Id = Id,
+                User = User?.Clone(false),
+                Notes = Notes,
+                CreatedOn = CreatedOn,
+                PrivateNotes = PrivateNotes,
+                Details = Details?.Clone(false)
+            };
+        }
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/TimeEntry.cs b/src/redmine-net-api/Types/TimeEntry.cs
index a6691bdb..afb8d110 100644
--- a/src/redmine-net-api/Types/TimeEntry.cs
+++ b/src/redmine-net-api/Types/TimeEntry.cs
@@ -34,6 +34,7 @@ namespace Redmine.Net.Api.Types
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     [XmlRoot(RedmineKeys.TIME_ENTRY)]
     public sealed class TimeEntry : Identifiable<TimeEntry>
+        , ICloneable<TimeEntry>
     {
         #region Properties
         private string comments;
@@ -303,7 +304,7 @@ public override int GetHashCode()
         /// 
         /// </summary>
         /// <returns></returns>
-        public object Clone()
+        public new TimeEntry Clone(bool resetId)
         {
             var timeEntry = new TimeEntry
             {
diff --git a/src/redmine-net-api/Types/Upload.cs b/src/redmine-net-api/Types/Upload.cs
index 00beb32f..ca2ac4ee 100644
--- a/src/redmine-net-api/Types/Upload.cs
+++ b/src/redmine-net-api/Types/Upload.cs
@@ -32,6 +32,7 @@ namespace Redmine.Net.Api.Types
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     [XmlRoot(RedmineKeys.UPLOAD)]
     public sealed class Upload : IXmlSerializable, IJsonSerializable, IEquatable<Upload>
+        , ICloneable<Upload>
     {
         #region Properties
         /// <summary>
@@ -234,5 +235,19 @@ public override int GetHashCode()
         /// <returns></returns>
         private string DebuggerDisplay => $"[Upload: Token={Token}, FileName={FileName}, ContentType={ContentType}, Description={Description}]";
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public Upload Clone(bool resetId)
+        {
+            return new Upload
+            {
+                Token = Token,
+                FileName = FileName,
+                ContentType = ContentType,
+                Description = Description
+            };
+        }
     }
 }
\ No newline at end of file
diff --git a/src/redmine-net-api/Types/Watcher.cs b/src/redmine-net-api/Types/Watcher.cs
index c3949e37..d413cab1 100644
--- a/src/redmine-net-api/Types/Watcher.cs
+++ b/src/redmine-net-api/Types/Watcher.cs
@@ -27,6 +27,7 @@ namespace Redmine.Net.Api.Types
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     [XmlRoot(RedmineKeys.USER)]
     public sealed class Watcher : Identifiable<Watcher>
+        ,ICloneable<Watcher>
         ,IValue
     {
         #region Implementation of IValue 
@@ -37,16 +38,23 @@ public sealed class Watcher : Identifiable<Watcher>
 
         #endregion
 
-        #region Implementation of ICloneable 
+        #region Implementation of ICloneable<T> 
         /// <summary>
         /// 
         /// </summary>
         /// <returns></returns>
-        public object Clone()
+        public new Watcher Clone(bool resetId)
         {
-            var watcher = new Watcher { Id = Id };
-            return watcher;
+            if (resetId)
+            {
+                return new Watcher();
+            }
+            return new Watcher
+            {
+                Id = Id
+            };
         }
+
         #endregion
 
         /// <summary>
@@ -54,6 +62,5 @@ public object Clone()
         /// </summary>
         /// <returns></returns>
         private string DebuggerDisplay => $"[{nameof(Watcher)}: {ToString()}]";
-
     }
 }
\ No newline at end of file