diff --git a/col.go b/col.go
index ee7f6e622c..cb84a10d90 100644
--- a/col.go
+++ b/col.go
@@ -546,7 +546,7 @@ func (ws *xlsxWorksheet) setColWidth(minVal, maxVal int, width float64) {
 // and check the worksheet columns.
 func flatCols(col xlsxCol, cols []xlsxCol, replacer func(fc, c xlsxCol) xlsxCol) []xlsxCol {
 	var fc []xlsxCol
-	for i := col.Min; i <= col.Max; i++ {
+	for i := max(MinColumns, col.Min); i <= min(MaxColumns, col.Max); i++ {
 		var c xlsxCol
 		_ = deepcopy.Copy(&c, col)
 		c.Min, c.Max = i, i
@@ -561,7 +561,7 @@ func flatCols(col xlsxCol, cols []xlsxCol, replacer func(fc, c xlsxCol) xlsxCol)
 		return -1, false
 	}
 	for _, column := range cols {
-		for i := column.Min; i <= column.Max; i++ {
+		for i := max(MinColumns, column.Min); i <= min(MaxColumns, column.Max); i++ {
 			if idx, ok := inFlat(i, fc); ok {
 				fc[idx] = replacer(fc[idx], column)
 				continue
diff --git a/col_test.go b/col_test.go
index fcea60f668..24d9fef45d 100644
--- a/col_test.go
+++ b/col_test.go
@@ -436,6 +436,19 @@ func TestColWidth(t *testing.T) {
 
 	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestColWidth.xlsx")))
 	convertRowHeightToPixels(0)
+
+	t.Run("with_invalid_column_number", func(t *testing.T) {
+		f := NewFile()
+		ws, err := f.workSheetReader("Sheet1")
+		assert.NoError(t, err)
+		ws.Cols = &xlsxCols{Col: []xlsxCol{{Min: 0, Max: MaxColumns + 1, Width: float64Ptr(9)}}}
+		assert.NoError(t, f.SetColWidth("Sheet1", "A", "A", 12))
+		assert.Equal(t, len(ws.Cols.Col), MaxColumns)
+		width, err := f.GetColWidth("Sheet1", "A")
+		assert.NoError(t, err)
+		assert.Equal(t, 12.0, width)
+		assert.NoError(t, f.Close())
+	})
 }
 
 func TestGetColStyle(t *testing.T) {