diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index c360c17..1c68c90 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -3430,7 +3430,7 @@
         {
             var differentialFormat = new DifferentialFormat();
 
-            var diffFont = GetNewFont(new FontInfo { Font = cf.Style.Font as XLFont }, false);
+            var diffFont = GetNewFont(new FontInfo { Font = cf.Style.Value.Font }, false);
             if (diffFont?.HasChildren ?? false)
                 differentialFormat.Append(diffFont);
 
@@ -3462,7 +3462,7 @@
         {
             var differentialFormat = new DifferentialFormat();
 
-            var diffFont = GetNewFont(new FontInfo { Font = style.Font as XLFont }, false);
+            var diffFont = GetNewFont(new FontInfo { Font = style.Font }, false);
             if (diffFont?.HasChildren ?? false)
                 differentialFormat.Append(diffFont);
 
diff --git a/ClosedXML_Tests/Excel/Columns/ColumnTests.cs b/ClosedXML_Tests/Excel/Columns/ColumnTests.cs
index 0d13b93..a0571cd 100644
--- a/ClosedXML_Tests/Excel/Columns/ColumnTests.cs
+++ b/ClosedXML_Tests/Excel/Columns/ColumnTests.cs
@@ -242,7 +242,7 @@
         {
             var ws = new XLWorkbook().AddWorksheet("Sheet1") as XLWorksheet;
 
-            var column = new XLColumn(-1, new XLColumnParameters(ws, 0, false));
+            var column = new XLColumn(-1, new XLColumnParameters(ws, XLStyle.Default, false));
 
             Assert.IsFalse(column.RangeAddress.IsValid);
         }
diff --git a/ClosedXML_Tests/Excel/Rows/RowTests.cs b/ClosedXML_Tests/Excel/Rows/RowTests.cs
index 6453623..5314b54 100644
--- a/ClosedXML_Tests/Excel/Rows/RowTests.cs
+++ b/ClosedXML_Tests/Excel/Rows/RowTests.cs
@@ -259,7 +259,7 @@
         {
             var ws = new XLWorkbook().AddWorksheet("Sheet1") as XLWorksheet;
 
-            var row = new XLRow(-1, new XLRowParameters(ws, 0, false));
+            var row = new XLRow(-1, new XLRowParameters(ws, XLStyle.Default, false));
 
             Assert.IsFalse(row.RangeAddress.IsValid);
         }
diff --git a/ClosedXML_Tests/Resource/StyleReferenceFiles/ConditionalFormattingOrder/ConditionalFormattingOrder.xlsx b/ClosedXML_Tests/Resource/StyleReferenceFiles/ConditionalFormattingOrder/ConditionalFormattingOrder.xlsx
index 5f27c54..84c186d 100644
--- a/ClosedXML_Tests/Resource/StyleReferenceFiles/ConditionalFormattingOrder/ConditionalFormattingOrder.xlsx
+++ b/ClosedXML_Tests/Resource/StyleReferenceFiles/ConditionalFormattingOrder/ConditionalFormattingOrder.xlsx
Binary files differ
diff --git a/ClosedXML_Tests/Resource/StyleReferenceFiles/TransparentBackgroundFill/TransparentBackgroundFill.xlsx b/ClosedXML_Tests/Resource/StyleReferenceFiles/TransparentBackgroundFill/TransparentBackgroundFill.xlsx
index 3a12637..ffd35b3 100644
--- a/ClosedXML_Tests/Resource/StyleReferenceFiles/TransparentBackgroundFill/TransparentBackgroundFill.xlsx
+++ b/ClosedXML_Tests/Resource/StyleReferenceFiles/TransparentBackgroundFill/TransparentBackgroundFill.xlsx
Binary files differ