diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index cbadd34..c92a39d 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -2068,7 +2068,9 @@
                 case XLPivotTableSourceType.Range:
                     worksheetSource.Name = null;
                     worksheetSource.Reference = source.RangeAddress.ToStringRelative(includeSheet: false);
-                    worksheetSource.Sheet = source.RangeAddress.Worksheet.Name.EscapeSheetName();
+
+                    // Do not quote worksheet name with whitespace here - issue #955
+                    worksheetSource.Sheet = source.RangeAddress.Worksheet.Name; 
                     break;
 
                 case XLPivotTableSourceType.Table:
diff --git a/ClosedXML_Tests/Excel/PivotTables/XLPivotTableTests.cs b/ClosedXML_Tests/Excel/PivotTables/XLPivotTableTests.cs
index 7d95222..51a89bb 100644
--- a/ClosedXML_Tests/Excel/PivotTables/XLPivotTableTests.cs
+++ b/ClosedXML_Tests/Excel/PivotTables/XLPivotTableTests.cs
@@ -278,6 +278,71 @@
         }
 
         [Test]
+        public void SourceSheetWithWhitespace()
+        {
+            using (var ms = new MemoryStream())
+            {
+                TestHelper.CreateAndCompare(() =>
+                {
+                    // Based on .\ClosedXML\ClosedXML_Examples\PivotTables\PivotTables.cs
+                    // But with empty column for Month
+                    var pastries = new List<Pastry>
+                    {
+                        new Pastry("Croissant", 101, 150, 60.2, "", new DateTime(2016, 04, 21)),
+                        new Pastry("Croissant", 101, 250, 50.42, "", new DateTime(2016, 05, 03)),
+                        new Pastry("Croissant", 101, 134, 22.12, "", new DateTime(2016, 06, 24)),
+                        new Pastry("Doughnut", 102, 250, 89.99, "", new DateTime(2017, 04, 23)),
+                        new Pastry("Doughnut", 102, 225, 70, "", new DateTime(2016, 05, 24)),
+                        new Pastry("Doughnut", 102, 210, 75.33, "", new DateTime(2016, 06, 02)),
+                        new Pastry("Bearclaw", 103, 134, 10.24, "", new DateTime(2016, 04, 27)),
+                        new Pastry("Bearclaw", 103, 184, 33.33, "", new DateTime(2016, 05, 20)),
+                        new Pastry("Bearclaw", 103, 124, 25, "", new DateTime(2017, 06, 05)),
+                        new Pastry("Danish", 104, 394, -20.24, "", null),
+                        new Pastry("Danish", 104, 190, 60, "", new DateTime(2017, 05, 08)),
+                        new Pastry("Danish", 104, 221, 24.76, "", new DateTime(2016, 06, 21)),
+
+                        // Deliberately add different casings of same string to ensure pivot table doesn't duplicate it.
+                        new Pastry("Scone", 105, 135, 0, "", new DateTime(2017, 04, 22)),
+                        new Pastry("SconE", 105, 122, 5.19, "", new DateTime(2017, 05, 03)),
+                        new Pastry("SCONE", 105, 243, 44.2, "", new DateTime(2017, 06, 14)),
+
+                        // For ContainsBlank and integer rows/columns test
+                        new Pastry("Scone", null, 255, 18.4, "", null),
+                    };
+
+                    var wb = new XLWorkbook();
+
+                    var sheet = wb.Worksheets.Add("Pastry Sales Data");
+                    // Insert our list of pastry data into the "PastrySalesData" sheet at cell 1,1
+                    var table = sheet.Cell(1, 1).InsertTable(pastries, "PastrySalesData", true);
+                    sheet.Cell("F11").Style.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
+                    sheet.Columns().AdjustToContents();
+
+                    IXLWorksheet ptSheet;
+                    IXLPivotTable pt;
+
+                    // Add a new sheet for our pivot table
+                    ptSheet = wb.Worksheets.Add("pvt");
+
+                    // Create the pivot table, using the data from the "PastrySalesData" table
+                    pt = ptSheet.PivotTables.Add("pvt", ptSheet.Cell(1, 1), table.AsRange());
+                    pt.ColumnLabels.Add("Name");
+                    pt.RowLabels.Add("Month");
+
+                    // The values in our table will come from the "NumberOfOrders" field
+                    // The default calculation setting is a total of each row/column
+                    pt.Values.Add("NumberOfOrders", "NumberOfOrdersPercentageOfBearclaw")
+                        .ShowAsPercentageFrom("Name").And("Bearclaw")
+                        .NumberFormat.Format = "0%";
+
+                    ptSheet.Columns().AdjustToContents();
+
+                    return wb;
+                }, @"Other\PivotTableReferenceFiles\SourceSheetWithWhitespace\outputfile.xlsx");
+            }
+        }
+
+        [Test]
         public void PivotTableWithNoneTheme()
         {
             using (var stream = TestHelper.GetStreamFromResource(TestHelper.GetResourcePath(@"Other\PivotTableReferenceFiles\PivotTableWithNoneTheme\inputfile.xlsx")))
diff --git a/ClosedXML_Tests/Resource/Other/PivotTableReferenceFiles/SourceSheetWithWhitespace/outputfile.xlsx b/ClosedXML_Tests/Resource/Other/PivotTableReferenceFiles/SourceSheetWithWhitespace/outputfile.xlsx
new file mode 100644
index 0000000..77bfc8d
--- /dev/null
+++ b/ClosedXML_Tests/Resource/Other/PivotTableReferenceFiles/SourceSheetWithWhitespace/outputfile.xlsx
Binary files differ