diff --git a/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs b/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs
index 3f57c20..0c21e4c 100644
--- a/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs
+++ b/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs
@@ -2,6 +2,12 @@
 
 namespace ClosedXML.Excel
 {
+    public enum XLNamedRangeScope
+    {
+        Worksheet,
+        Workbook
+    }
+
     public interface IXLNamedRange
     {
         /// <summary>
@@ -35,6 +41,11 @@
         Boolean Visible { get; set; }
 
         /// <summary>
+        /// Gets the scope of this named range.
+        /// </summary>
+        XLNamedRangeScope Scope { get; }
+
+        /// <summary>
         /// Adds the specified range to this named range.
         /// <para>Note: A named range can point to multiple ranges.</para>
         /// </summary>
diff --git a/ClosedXML/Excel/NamedRanges/XLNamedRange.cs b/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
index ce7e2a5..b4a2799 100644
--- a/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
+++ b/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
@@ -53,6 +53,8 @@
 
         public Boolean Visible { get; set; }
 
+        public XLNamedRangeScope Scope { get { return _namedRanges.Scope; } }
+
         public IXLRanges Add(XLWorkbook workbook, String rangeAddress)
         {
             var ranges = new XLRanges();
diff --git a/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs b/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
index 9a9a2ee..ae0273a 100644
--- a/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
+++ b/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
@@ -9,16 +9,19 @@
         private readonly Dictionary<String, IXLNamedRange> _namedRanges = new Dictionary<String, IXLNamedRange>();
         internal XLWorkbook Workbook { get; set; }
         internal XLWorksheet Worksheet { get; set; }
+        internal XLNamedRangeScope Scope { get; }
 
         public XLNamedRanges(XLWorksheet worksheet)
             : this(worksheet.Workbook)
         {
             Worksheet = worksheet;
+            Scope = XLNamedRangeScope.Worksheet;
         }
 
         public XLNamedRanges(XLWorkbook workbook)
         {
             Workbook = workbook;
+            Scope = XLNamedRangeScope.Workbook;
         }
 
         #region IXLNamedRanges Members
@@ -70,14 +73,20 @@
                 {
                     if (XLHelper.IsValidRangeAddress(rangeAddress))
                     {
-                        var range = Worksheet?.Range(rangeAddress) ?? Workbook.Range(rangeAddress);
+                        IXLRange range = null;
+                        if (Scope == XLNamedRangeScope.Worksheet)
+                            range = Worksheet.Range(rangeAddress);
+                        else if (Scope == XLNamedRangeScope.Workbook)
+                            range = Workbook.Range(rangeAddress);
+                        else
+                            throw new NotSupportedException($"Scope {Scope} is not supported");
 
                         if (range == null)
                             throw new ArgumentException(string.Format(
                                 "The range address '{0}' for the named range '{1}' is not a valid range.", rangeAddress,
                                 rangeName));
 
-                        if (Worksheet == null || !XLHelper.NamedRangeReferenceRegex.Match(range.ToString()).Success)
+                        if (Scope == XLNamedRangeScope.Workbook || !XLHelper.NamedRangeReferenceRegex.Match(range.ToString()).Success)
                             throw new ArgumentException(
                                 "For named ranges in the workbook scope, specify the sheet name in the reference.");
 
@@ -143,9 +152,7 @@
         {
             if (_namedRanges.TryGetValue(name, out range)) return true;
 
-            if (Worksheet != null)
-                range = Worksheet.NamedRange(name);
-            else
+            if (Scope == XLNamedRangeScope.Workbook)
                 range = Workbook.NamedRange(name);
 
             return range != null;
@@ -155,10 +162,10 @@
         {
             if (_namedRanges.ContainsKey(name)) return true;
 
-            if (Worksheet != null)
-                return Worksheet.NamedRange(name) != null;
-            else
+            if (Scope == XLNamedRangeScope.Workbook)
                 return Workbook.NamedRange(name) != null;
+            else
+                return false;
         }
     }
 }
diff --git a/ClosedXML_Tests/Excel/NamedRanges/NamedRangesTests.cs b/ClosedXML_Tests/Excel/NamedRanges/NamedRangesTests.cs
index 91779e4..5054c1e 100644
--- a/ClosedXML_Tests/Excel/NamedRanges/NamedRangesTests.cs
+++ b/ClosedXML_Tests/Excel/NamedRanges/NamedRangesTests.cs
@@ -36,6 +36,10 @@
             Assert.AreEqual("Sheet1!$C$3,Sheet1!$C$4:$D$4,Sheet2!$D$3:$D$4,Sheet1!$7:$8,Sheet1!$G:$H",
                 sheet1.NamedRanges.First().RefersTo);
             Assert.AreEqual("Sheet1!B2,Sheet2!A1", sheet2.NamedRanges.First().RefersTo);
+
+            wb.NamedRanges.ForEach(nr => Assert.AreEqual(XLNamedRangeScope.Workbook, nr.Scope));
+            sheet1.NamedRanges.ForEach(nr => Assert.AreEqual(XLNamedRangeScope.Worksheet, nr.Scope));
+            sheet2.NamedRanges.ForEach(nr => Assert.AreEqual(XLNamedRangeScope.Worksheet, nr.Scope));
         }
 
         [Test]
@@ -54,6 +58,7 @@
             Boolean result1 = wb.NamedRanges.TryGetValue("Sheet1!Name", out IXLNamedRange range1);
             Assert.IsTrue(result1);
             Assert.IsNotNull(range1);
+            Assert.AreEqual(XLNamedRangeScope.Worksheet, range1.Scope);
 
             Boolean result2 = wb.NamedRanges.TryGetValue("Sheet1!NameX", out IXLNamedRange range2);
             Assert.IsFalse(result2);