diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
index a99e010..a2958fb 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
@@ -8,11 +8,7 @@
 
     internal class XLNamedRange: IXLNamedRange
     {
-        private static readonly Regex _namedRangeReferenceRegex =
-            new Regex(
-                @"^('?(?<Sheet>[^'!]+)'?!(?<Range>.+))|((?<Table>[^\[]+)\[(?<Column>[^\]]+)\])$",
-                RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.ExplicitCapture
-            );
+
         private List<String> _rangeList = new List<String>();
         private readonly XLNamedRanges _namedRanges;
         public XLNamedRange(XLNamedRanges namedRanges , String rangeName, String range,  String comment = null)
@@ -39,7 +35,7 @@
                 var ranges = new XLRanges();
                 foreach (var rangeToAdd in 
                    from rangeAddress in _rangeList.SelectMany(c=>c.Split(',')).Where(s=>s[0] != '"')
-                   let match = _namedRangeReferenceRegex.Match(rangeAddress)
+                   let match = XLHelper.NamedRangeReferenceRegex.Match(rangeAddress)
                    select
                        match.Groups["Sheet"].Success
                        ?  _namedRanges.Workbook.WorksheetsInternal.Worksheet(match.Groups["Sheet"].Value).Range(match.Groups["Range"].Value) as IXLRangeBase
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
index 687b1a1..7155e2d 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 
 namespace ClosedXML.Excel
 {
@@ -551,7 +552,14 @@
             var targetSheet = (XLWorksheet)workbook.WorksheetsInternal.Add(newSheetName, position);
 
             Internals.CellsCollection.GetCells().ForEach(c => targetSheet.Cell(c.Address).CopyFrom(c, false));
-            DataValidations.ForEach(dv => targetSheet.DataValidations.Add(new XLDataValidation(dv)));
+            DataValidations.ForEach(dv =>
+                                        {
+                                            var newDv = new XLDataValidation(dv);
+                                            newDv.Value = ReplaceRelativeSheet(newSheetName, dv.Value);
+                                            newDv.MinValue = ReplaceRelativeSheet(newSheetName, dv.MinValue);
+                                            newDv.MaxValue = ReplaceRelativeSheet(newSheetName, dv.MaxValue);
+                                            targetSheet.DataValidations.Add(newDv);
+                                        });
             Internals.ColumnsCollection.ForEach(
                 kp => targetSheet.Internals.ColumnsCollection.Add(kp.Key, new XLColumn(kp.Value)));
             Internals.RowsCollection.ForEach(kp => targetSheet.Internals.RowsCollection.Add(kp.Key, new XLRow(kp.Value)));
@@ -608,6 +616,34 @@
             return targetSheet;
         }
 
+        private String ReplaceRelativeSheet(string newSheetName, String value)
+        {
+            if (StringExtensions.IsNullOrWhiteSpace(value)) return value;
+
+            var newValue = new StringBuilder();
+            var addresses = value.Split(',');
+            foreach (var address in addresses)
+            {
+                var pair = address.Split('!');
+                if (pair.Length == 2)
+                {
+                    String sheetName = pair[0];
+                    if (sheetName.StartsWith("'"))
+                        sheetName = sheetName.Substring(1, sheetName.Length - 2);
+
+                    String name = sheetName.ToLower().Equals(Name.ToLower())
+                                      ? newSheetName
+                                      : sheetName;
+                    newValue.Append(String.Format("'{0}'!{1}", name, pair[1]));
+                }
+                else
+                {
+                    newValue.Append(address);
+                }
+            }
+            return newValue.ToString();
+        }
+
         public new IXLHyperlinks Hyperlinks { get; private set; }
 
         IXLDataValidations IXLWorksheet.DataValidations
diff --git a/ClosedXML/ClosedXML/ClosedXML/ExcelHelper.cs b/ClosedXML/ClosedXML/ClosedXML/ExcelHelper.cs
index 1a3c9f1..4a84b09 100644
--- a/ClosedXML/ClosedXML/ClosedXML/ExcelHelper.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/ExcelHelper.cs
@@ -160,25 +160,14 @@
             + @"\Z"
             );
 
+        public static readonly Regex NamedRangeReferenceRegex =
+            new Regex( @"^('?(?<Sheet>[^'!]+)'?!(?<Range>.+))|((?<Table>[^\[]+)\[(?<Column>[^\]]+)\])$",
+                RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.ExplicitCapture
+            );
+
         public static Boolean IsValidRangeAddress(String rangeAddress)
         {
             return A1SimpleRegex.IsMatch(rangeAddress);
-            //if (StringExtensions.IsNullOrWhiteSpace(rangeAddress))
-            //    return false;
-
-            //string addressToUse = rangeAddress.Contains("!")
-            //                          ? rangeAddress.Substring(rangeAddress.IndexOf("!") + 1)
-            //                          : rangeAddress;
-
-            //if (addressToUse.Contains(':'))
-            //{
-            //    var arrRange = addressToUse.Split(':');
-            //    string firstPart = arrRange[0];
-            //    string secondPart = arrRange[1];
-            //    return IsValidA1Address(firstPart) && IsValidA1Address(secondPart);
-            //}
-
-            //return IsValidA1Address(addressToUse);
         }
 
         public static int GetRowFromAddress1(string cellAddressString)
diff --git a/ClosedXML/ClosedXML/ClosedXML_Tests/Resource/Examples/Misc/DataValidation.xlsx b/ClosedXML/ClosedXML/ClosedXML_Tests/Resource/Examples/Misc/DataValidation.xlsx
index 566addb..8fba4bc 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Tests/Resource/Examples/Misc/DataValidation.xlsx
+++ b/ClosedXML/ClosedXML/ClosedXML_Tests/Resource/Examples/Misc/DataValidation.xlsx
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