Index: src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationSheet.java
===================================================================
--- src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationSheet.java	(revision 1848483)
+++ src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationSheet.java	(working copy)
@@ -34,11 +34,9 @@
 
     private final XSSFSheet _xs;
     private Map<CellKey, EvaluationCell> _cellCache;
-    private int _lastDefinedRow = -1;
 
     public XSSFEvaluationSheet(XSSFSheet sheet) {
         _xs = sheet;
-        _lastDefinedRow = _xs.getLastRowNum();
     }
 
     public XSSFSheet getXSSFSheet() {
@@ -51,7 +49,7 @@
      */
     @Override
     public int getLastRowNum() {
-        return _lastDefinedRow;
+        return _xs.getLastRowNum();
     }
     
     /* (non-JavaDoc), inherit JavaDoc from EvaluationWorkbook
@@ -60,7 +58,6 @@
     @Override
     public void clearAllCachedResultValues() {
         _cellCache = null;
-        _lastDefinedRow = _xs.getLastRowNum();
     }
     
     @Override
@@ -67,7 +64,9 @@
     public EvaluationCell getCell(int rowIndex, int columnIndex) {
         // shortcut evaluation if reference is outside the bounds of existing data
         // see issue #61841 for impact on VLOOKUP in particular
-        if (rowIndex > _lastDefinedRow) return null;
+        if (rowIndex > getLastRowNum()) {
+            return null;                
+        }
         
         // cache for performance: ~30% speedup due to caching
         if (_cellCache == null) {
Index: src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFSheet.java
===================================================================
--- src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFSheet.java	(revision 1848483)
+++ src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFSheet.java	(working copy)
@@ -165,6 +165,7 @@
     protected CTWorksheet worksheet;
 
     private final SortedMap<Integer, XSSFRow> _rows = new TreeMap<>();
+    private int _lastRowNum=0;
     private List<XSSFHyperlink> hyperlinks;
     private ColumnHelper columnHelper;
     private CommentsTable sheetComments;
@@ -263,6 +264,7 @@
 
     private void initRows(CTWorksheet worksheetParam) {
         _rows.clear();
+        _lastRowNum=0;
         tables = new TreeMap<>();
         sharedFormulas = new HashMap<>();
         arrayFormulas = new ArrayList<>();
@@ -782,6 +784,7 @@
         XSSFRow r = new XSSFRow(ctRow, this);
         r.setRowNum(rownum);
         _rows.put(rownumI, r);
+        _lastRowNum = Math.max(_lastRowNum, rownum);
         return r;
     }
 
@@ -1211,7 +1214,7 @@
 
     @Override
     public int getLastRowNum() {
-        return _rows.isEmpty() ? 0 : _rows.lastKey();
+        return _lastRowNum;
     }
 
     @Override
@@ -2016,6 +2019,7 @@
         // this is not the physical row number!
         final int idx = _rows.headMap(rowNumI).size();
         _rows.remove(rowNumI);
+        _lastRowNum = _rows.isEmpty() ? 0 : _rows.lastKey();
         worksheet.getSheetData().removeRow(idx);
 
         // also remove any comment located in that row
@@ -3063,6 +3067,7 @@
             final Integer rownumI = new Integer(r.getRowNum()); // NOSONAR
             _rows.put(rownumI, r);
         }
+        _lastRowNum = _rows.isEmpty() ? 0 : _rows.lastKey();
     }
 
     // remove all rows which will be overwritten