diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index fd3db5e..c70febf 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -5613,6 +5613,8 @@
                 openXmlCell.CellValue = cellValue;
                 return;
             }
+            else
+                openXmlCell.CellValue = null;
 
             var dataType = xlCell.DataType;
             if (dataType == XLDataType.Text)
diff --git a/ClosedXML_Tests/Excel/Clearing/ClearingTests.cs b/ClosedXML_Tests/Excel/Clearing/ClearingTests.cs
index 99e8bb2..1b2928f 100644
--- a/ClosedXML_Tests/Excel/Clearing/ClearingTests.cs
+++ b/ClosedXML_Tests/Excel/Clearing/ClearingTests.cs
@@ -1,6 +1,7 @@
 using ClosedXML.Excel;
 using NUnit.Framework;
 using System;
+using System.IO;
 using System.Linq;
 
 namespace ClosedXML_Tests
@@ -100,164 +101,185 @@
         [Test]
         public void WorksheetClearContents()
         {
+            using (var wb = SetupWorkbook())
             {
-                using (var wb = SetupWorkbook())
+                var ws = wb.Worksheets.First();
+
+                ws.Clear(XLClearOptions.Contents);
+
+                foreach (var c in ws.Range("A1:A3").Cells())
                 {
-                    var ws = wb.Worksheets.First();
-
-                    ws.Clear(XLClearOptions.Contents);
-
-                    foreach (var c in ws.Range("A1:A3").Cells())
-                    {
-                        Assert.IsTrue(c.IsEmpty());
-                        Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
-                        Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
-                        Assert.IsTrue(ws.ConditionalFormats.Any());
-                        Assert.IsTrue(c.HasComment);
-                    }
-
-                    Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
-
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
-                    Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
+                    Assert.IsTrue(c.IsEmpty());
+                    Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
+                    Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
+                    Assert.IsTrue(ws.ConditionalFormats.Any());
+                    Assert.IsTrue(c.HasComment);
                 }
+
+                Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
+
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
+                Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
             }
         }
 
         [Test]
         public void WorksheetClearDataType()
         {
+            using (var wb = SetupWorkbook())
             {
-                using (var wb = SetupWorkbook())
+                var ws = wb.Worksheets.First();
+
+                ws.Clear(XLClearOptions.DataType);
+
+                foreach (var c in ws.Range("A1:A3").Cells())
                 {
-                    var ws = wb.Worksheets.First();
-
-                    ws.Clear(XLClearOptions.DataType);
-
-                    foreach (var c in ws.Range("A1:A3").Cells())
-                    {
-                        Assert.IsFalse(c.IsEmpty());
-                        Assert.AreEqual(XLDataType.Text, c.DataType);
-                        Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
-                        Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
-                        Assert.IsTrue(ws.ConditionalFormats.Any());
-                        Assert.IsTrue(c.HasComment);
-                    }
-
-                    Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
+                    Assert.IsFalse(c.IsEmpty());
+                    Assert.AreEqual(XLDataType.Text, c.DataType);
+                    Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
+                    Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
+                    Assert.IsTrue(ws.ConditionalFormats.Any());
+                    Assert.IsTrue(c.HasComment);
                 }
+
+                Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
             }
         }
 
         [Test]
         public void WorksheetClearNormalFormats()
         {
+            using (var wb = SetupWorkbook())
             {
-                using (var wb = SetupWorkbook())
+                var ws = wb.Worksheets.First();
+
+                ws.Clear(XLClearOptions.NormalFormats);
+
+                foreach (var c in ws.Range("A1:A3").Cells())
                 {
-                    var ws = wb.Worksheets.First();
-
-                    ws.Clear(XLClearOptions.NormalFormats);
-
-                    foreach (var c in ws.Range("A1:A3").Cells())
-                    {
-                        Assert.IsFalse(c.IsEmpty());
-                        Assert.AreEqual(ws.Style.Fill.BackgroundColor, c.Style.Fill.BackgroundColor);
-                        Assert.AreEqual(ws.Style.Font.FontColor, c.Style.Font.FontColor);
-                        Assert.IsTrue(ws.ConditionalFormats.Any());
-                        Assert.IsTrue(c.HasComment);
-                    }
-
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
-                    Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
-
-                    Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
+                    Assert.IsFalse(c.IsEmpty());
+                    Assert.AreEqual(ws.Style.Fill.BackgroundColor, c.Style.Fill.BackgroundColor);
+                    Assert.AreEqual(ws.Style.Font.FontColor, c.Style.Font.FontColor);
+                    Assert.IsTrue(ws.ConditionalFormats.Any());
+                    Assert.IsTrue(c.HasComment);
                 }
+
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
+                Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
+
+                Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
             }
         }
 
         [Test]
         public void WorksheetClearConditionalFormats()
         {
+            using (var wb = SetupWorkbook())
             {
-                using (var wb = SetupWorkbook())
+                var ws = wb.Worksheets.First();
+
+                ws.Clear(XLClearOptions.ConditionalFormats);
+
+                foreach (var c in ws.Range("A1:A3").Cells())
                 {
-                    var ws = wb.Worksheets.First();
-
-                    ws.Clear(XLClearOptions.ConditionalFormats);
-
-                    foreach (var c in ws.Range("A1:A3").Cells())
-                    {
-                        Assert.IsFalse(c.IsEmpty());
-                        Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
-                        Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
-                        Assert.IsFalse(ws.ConditionalFormats.Any());
-                        Assert.IsTrue(c.HasComment);
-                    }
-
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
-                    Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
-
-                    Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
+                    Assert.IsFalse(c.IsEmpty());
+                    Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
+                    Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
+                    Assert.IsFalse(ws.ConditionalFormats.Any());
+                    Assert.IsTrue(c.HasComment);
                 }
+
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
+                Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
+
+                Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
             }
         }
 
         [Test]
         public void WorksheetClearComments()
         {
+            using (var wb = SetupWorkbook())
             {
-                using (var wb = SetupWorkbook())
+                var ws = wb.Worksheets.First();
+
+                ws.Clear(XLClearOptions.Comments);
+
+                foreach (var c in ws.Range("A1:A3").Cells())
                 {
-                    var ws = wb.Worksheets.First();
-
-                    ws.Clear(XLClearOptions.Comments);
-
-                    foreach (var c in ws.Range("A1:A3").Cells())
-                    {
-                        Assert.IsFalse(c.IsEmpty());
-                        Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
-                        Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
-                        Assert.IsTrue(ws.ConditionalFormats.Any());
-                        Assert.IsFalse(c.HasComment);
-                    }
-
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
-                    Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
-
-                    Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
+                    Assert.IsFalse(c.IsEmpty());
+                    Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
+                    Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
+                    Assert.IsTrue(ws.ConditionalFormats.Any());
+                    Assert.IsFalse(c.HasComment);
                 }
+
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
+                Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
+
+                Assert.AreEqual("B1", ws.Cell("A1").DataValidation.Value);
             }
         }
 
         [Test]
         public void WorksheetClearDataValidation()
         {
+            using (var wb = SetupWorkbook())
+            {
+                var ws = wb.Worksheets.First();
+
+                ws.Clear(XLClearOptions.DataValidation);
+
+                foreach (var c in ws.Range("A1:A3").Cells())
+                {
+                    Assert.IsFalse(c.IsEmpty());
+                    Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
+                    Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
+                    Assert.IsTrue(ws.ConditionalFormats.Any());
+                    Assert.IsTrue(c.HasComment);
+                }
+
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
+                Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
+                Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
+
+                Assert.AreEqual(string.Empty, ws.Cell("A1").DataValidation.Value);
+            }
+        }
+
+        [Test]
+        public void DeleteClearedCellValue()
+        {
+            using (var ms = new MemoryStream())
             {
                 using (var wb = SetupWorkbook())
                 {
                     var ws = wb.Worksheets.First();
+                    Assert.AreEqual("Hello world!", ws.Cell("A1").GetString());
+                    Assert.AreEqual(new DateTime(2018, 1, 15), ws.Cell("A3").GetDateTime());
 
-                    ws.Clear(XLClearOptions.DataValidation);
+                    wb.SaveAs(ms);
+                }
 
-                    foreach (var c in ws.Range("A1:A3").Cells())
-                    {
-                        Assert.IsFalse(c.IsEmpty());
-                        Assert.AreEqual(backgroundColor, c.Style.Fill.BackgroundColor);
-                        Assert.AreEqual(foregroundColor, c.Style.Font.FontColor);
-                        Assert.IsTrue(ws.ConditionalFormats.Any());
-                        Assert.IsTrue(c.HasComment);
-                    }
+                using (var wb = new XLWorkbook(ms))
+                {
+                    var ws = wb.Worksheets.First();
+                    ws.Clear(XLClearOptions.Contents);
+                    Assert.AreEqual("", ws.Cell("A1").GetString());
+                    Assert.Throws<FormatException>(() => ws.Cell("A3").GetDateTime());
 
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A1").DataType);
-                    Assert.AreEqual(XLDataType.Text, ws.Cell("A2").DataType);
-                    Assert.AreEqual(XLDataType.DateTime, ws.Cell("A3").DataType);
+                    wb.Save();
+                }
 
-                    Assert.AreEqual(string.Empty, ws.Cell("A1").DataValidation.Value);
+                using (var wb = new XLWorkbook(ms))
+                {
+                    var ws = wb.Worksheets.First();
+                    Assert.AreEqual("", ws.Cell("A1").GetString());
+                    Assert.Throws<FormatException>(() => ws.Cell("A3").GetDateTime());
                 }
             }
         }