diff --git a/main/NPOI.Core.csproj b/main/NPOI.Core.csproj
index 93aefb7ea..54cc21d1e 100644
--- a/main/NPOI.Core.csproj
+++ b/main/NPOI.Core.csproj
@@ -15,7 +15,7 @@
 
   <ItemGroup>
     <PackageReference Include="Enums.NET" Version="4.0.1" />
-    <PackageReference Include="ExtendedNumerics.BigDecimal" Version="2025.1000.2.122" />
+    <PackageReference Include="ExtendedNumerics.BigDecimal" Version="2025.1001.2.129" />
     <PackageReference Include="MathNet.Numerics.Signed" Version="5.0.0" />
     <PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.0" />
     <PackageReference Include="BouncyCastle.Cryptography" Version="2.3.1" />
diff --git a/testcases/ooxml/XSSF/UserModel/TestXSSFWorkbook.cs b/testcases/ooxml/XSSF/UserModel/TestXSSFWorkbook.cs
index 8d15d514f..ddafe36d3 100644
--- a/testcases/ooxml/XSSF/UserModel/TestXSSFWorkbook.cs
+++ b/testcases/ooxml/XSSF/UserModel/TestXSSFWorkbook.cs
@@ -1027,7 +1027,6 @@ public void TestBug56957CloseWorkbook()
             FileInfo file = TempFile.CreateTempFile("TestBug56957_", ".xlsx");
             //String dateExp = "Sun Nov 09 00:00:00 CET 2014";
             DateTime dateExp = LocaleUtil.GetLocaleCalendar(2014, 11, 9);
-            IWorkbook workbook = null;
             try
             {
                 // as the file is written to, we make a copy before actually working on it
@@ -1036,41 +1035,39 @@ public void TestBug56957CloseWorkbook()
                 Assert.IsTrue(file.Exists);
 
                 // read-only mode works!
-                workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ));
-                var dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
-                Assert.AreEqual(dateExp, dateAct);
-                workbook.Close();
-                workbook = null;
+                using(var workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ)))
+                {
+                    var dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
+                    Assert.AreEqual(dateExp, dateAct);
+                }
 
-                workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ));
-                dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
-                Assert.AreEqual(dateExp, dateAct);
-                workbook.Close();
-                workbook = null;
+                using(var workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ)))
+                {
+                    var dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
+                    Assert.AreEqual(dateExp, dateAct);
+                }
 
                 // now check read/write mode
-                workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ_WRITE));
-                dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
-                Assert.AreEqual(dateExp, dateAct);
-                workbook.Close();
-                workbook = null;
+                using(var workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ_WRITE)))
+                {
+                    var dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
+                    Assert.AreEqual(dateExp, dateAct);
+                }
 
-                workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ_WRITE));
-                dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
-                Assert.AreEqual(dateExp, dateAct);
-                workbook.Close();
-                workbook = null;
+                using(var workbook = WorkbookFactory.Create(OPCPackage.Open(file, PackageAccess.READ_WRITE)))
+                {
+                    var dateAct = workbook.GetSheetAt(0).GetRow(0).GetCell(0, MissingCellPolicy.CREATE_NULL_AS_BLANK).DateCellValue;
+                    Assert.AreEqual(dateExp, dateAct);
+                }
             }
             finally
             {
-                if (workbook != null)
-                {
-                    workbook.Close();
-                }
                 Assert.IsTrue(file.Exists);
+
                 file.Delete();
                 file.Refresh();
-                Assert.IsTrue(!file.Exists);
+
+                Assert.IsFalse(file.Exists);
             }
         }