diff --git a/components/fpspreadsheet/tests/testbiff8_1899.xls b/components/fpspreadsheet/tests/testbiff8_1899.xls
index c4af4f2e4..0e5058050 100644
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diff --git a/components/fpspreadsheet/tests/testbiff8_1904.xls b/components/fpspreadsheet/tests/testbiff8_1904.xls
index 3e01305a8..afd8dfe46 100644
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diff --git a/components/fpspreadsheet/tests/testodf_1899.ods b/components/fpspreadsheet/tests/testodf_1899.ods
index 15f28cf6b..abe07c4f2 100644
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diff --git a/components/fpspreadsheet/tests/testodf_1904.ods b/components/fpspreadsheet/tests/testodf_1904.ods
index 8d1c9adda..9e1b21e14 100644
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diff --git a/components/fpspreadsheet/tests/testooxml_1899.xlsx b/components/fpspreadsheet/tests/testooxml_1899.xlsx
index 6d3b1fa7c..4ff383c19 100644
Binary files a/components/fpspreadsheet/tests/testooxml_1899.xlsx and b/components/fpspreadsheet/tests/testooxml_1899.xlsx differ
diff --git a/components/fpspreadsheet/tests/testooxml_1904.xlsx b/components/fpspreadsheet/tests/testooxml_1904.xlsx
index e2d970e1e..aa3da7ba2 100644
Binary files a/components/fpspreadsheet/tests/testooxml_1904.xlsx and b/components/fpspreadsheet/tests/testooxml_1904.xlsx differ
diff --git a/components/fpspreadsheet/xlscommon.pas b/components/fpspreadsheet/xlscommon.pas
index 45865d742..83dc528fe 100644
--- a/components/fpspreadsheet/xlscommon.pas
+++ b/components/fpspreadsheet/xlscommon.pas
@@ -1197,6 +1197,12 @@ var
   err: TsErrorValue;
   ok: Boolean;
   cell: PCell;
+
+
+
+
+
+  fmt: TsCellFormat;
 begin
   { Index to XF Record }
   ReadRowColXF(AStream, ARow, ACol, XF);
@@ -1217,7 +1223,9 @@ begin
     InitCell(ARow, ACol, FVirtualCell);
     cell := @FVirtualCell;
   end else
-    cell := FWorksheet.AddCell(ARow, ACol);    // "Real" cell
+    cell := FWorksheet.GetCell(ARow, ACol);    // "Real" cell
+    // Don't call "AddCell" because, if the cell belongs to a shared formula, it
+    // already has been created before, and then would exist in the tree twice.
 
   // Now determine the type of the formula result
   if (Data[6] = $FF) and (Data[7] = $FF) then
@@ -1243,9 +1251,9 @@ begin
     {Find out what cell type, set content type and value}
     ExtractNumberFormat(XF, nf, nfs);
     if IsDateTime(ResultFormula, nf, nfs, dt) then
-      FWorksheet.WriteDateTime(cell, dt, nf, nfs)
+      FWorksheet.WriteDateTime(cell, dt) //, nf, nfs)
     else
-      FWorksheet.WriteNumber(cell, ResultFormula, nf, nfs);
+      FWorksheet.WriteNumber(cell, ResultFormula); //, nf, nfs);
   end;
 
   { Formula token array }
@@ -2025,7 +2033,9 @@ begin
     InitCell(r1, c1, FVirtualCell);
     cell := @FVirtualCell;
   end else
-    cell := FWorksheet.AddCell(r1, c1);        // "Real" cell
+    cell := FWorksheet.GetCell(r1, c1);        // "Real" cell
+    // Don't use "AddCell" here because this cell already exists in files written
+    // by Excel, and this would destroy its formatting.
 
   // Unused
   AStream.ReadByte;