diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index 4c8af06..188d213 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -3443,7 +3443,11 @@
             SaveContext context)
         {
             var differentialFormat = new DifferentialFormat();
-            differentialFormat.Append(GetNewFont(new FontInfo { Font = cf.Style.Font as XLFont }, false));
+
+            var diffFont = GetNewFont(new FontInfo { Font = cf.Style.Font as XLFont }, false);
+            if (diffFont?.HasChildren ?? false)
+                differentialFormat.Append(diffFont);
+
             if (!String.IsNullOrWhiteSpace(cf.Style.NumberFormat.Format))
             {
                 var numberFormat = new NumberingFormat
@@ -3453,8 +3457,14 @@
                 };
                 differentialFormat.Append(numberFormat);
             }
-            differentialFormat.Append(GetNewFill(new FillInfo { Fill = cf.Style.Fill as XLFill }, differentialFillFormat: true, ignoreMod: false));
-            differentialFormat.Append(GetNewBorder(new BorderInfo { Border = cf.Style.Border as XLBorder }, false));
+
+            var diffFill = GetNewFill(new FillInfo { Fill = cf.Style.Fill as XLFill }, differentialFillFormat: true, ignoreMod: false);
+            if (diffFill?.HasChildren ?? false)
+                differentialFormat.Append(diffFill);
+
+            var diffBorder = GetNewBorder(new BorderInfo { Border = cf.Style.Border as XLBorder }, false);
+            if (diffBorder?.HasChildren ?? false)
+                differentialFormat.Append(diffBorder);
 
             differentialFormats.Append(differentialFormat);
 
@@ -3465,7 +3475,11 @@
             SaveContext context)
         {
             var differentialFormat = new DifferentialFormat();
-            differentialFormat.Append(GetNewFont(new FontInfo { Font = style.Font as XLFont }, false));
+
+            var diffFont = GetNewFont(new FontInfo { Font = style.Font as XLFont }, false);
+            if (diffFont?.HasChildren ?? false)
+                differentialFormat.Append(diffFont);
+
             if (!String.IsNullOrWhiteSpace(style.NumberFormat.Format) || style.NumberFormat.NumberFormatId != 0)
             {
                 var numberFormat = new NumberingFormat();
@@ -3489,8 +3503,14 @@
 
                 differentialFormat.Append(numberFormat);
             }
-            differentialFormat.Append(GetNewFill(new FillInfo { Fill = style.Fill as XLFill }, differentialFillFormat: true, ignoreMod: false));
-            differentialFormat.Append(GetNewBorder(new BorderInfo { Border = style.Border as XLBorder }, false));
+
+            var diffFill = GetNewFill(new FillInfo { Fill = style.Fill as XLFill }, differentialFillFormat: true, ignoreMod: false);
+            if (diffFill?.HasChildren ?? false)
+                differentialFormat.Append(diffFill);
+
+            var diffBorder = GetNewBorder(new BorderInfo { Border = style.Border as XLBorder }, false);
+            if (diffBorder?.HasChildren ?? false)
+                differentialFormat.Append(diffBorder);
 
             differentialFormats.Append(differentialFormat);
 
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFContains.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFContains.xlsx
index a0c3791..8e4adf1 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFContains.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFContains.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFDatesOccurring.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFDatesOccurring.xlsx
index 6ec8da4..94f5caa 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFDatesOccurring.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFDatesOccurring.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEndsWith.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEndsWith.xlsx
index bfb06cd..80d08b7 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEndsWith.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEndsWith.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsNumber.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsNumber.xlsx
index bbfa6d4..13f828d 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsNumber.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsNumber.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsString.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsString.xlsx
index 4b6a481..8a25637 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsString.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFEqualsString.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsBlank.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsBlank.xlsx
index 84f5931..e6fa5ec 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsBlank.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsBlank.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsError.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsError.xlsx
index 0677026..ad1c538 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsError.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFIsError.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFMultipleConditions.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFMultipleConditions.xlsx
index d396c20..565af0c 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFMultipleConditions.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFMultipleConditions.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotBlank.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotBlank.xlsx
index f2a8f5b..8861be4 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotBlank.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotBlank.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotContains.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotContains.xlsx
index 22026b6..8656701 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotContains.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotContains.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsNumber.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsNumber.xlsx
index 4eabc7c..6e23b6a 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsNumber.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsNumber.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsString.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsString.xlsx
index 72e5631..d39adb0 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsString.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotEqualsString.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotError.xlsx b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotError.xlsx
index c808164..1ca0131 100644
--- a/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotError.xlsx
+++ b/ClosedXML_Tests/Resource/Examples/ConditionalFormatting/CFNotError.xlsx
Binary files differ