diff --git a/src/infrastructure/export/field/PhabricatorDoubleExportField.php b/src/infrastructure/export/field/PhabricatorDoubleExportField.php
--- a/src/infrastructure/export/field/PhabricatorDoubleExportField.php
+++ b/src/infrastructure/export/field/PhabricatorDoubleExportField.php
@@ -12,10 +12,10 @@
   }
 
   /**
-   * @phutil-external-symbol class PHPExcel_Cell_DataType
+   * @phutil-external-symbol class \PhpOffice\PhpSpreadsheet\Cell\DataType
    */
   public function formatPHPExcelCell($cell, $style) {
-    $cell->setDataType(PHPExcel_Cell_DataType::TYPE_NUMERIC);
+    $cell->setDataType(\PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC);
   }
 
   public function getCharacterWidth() {
diff --git a/src/infrastructure/export/field/PhabricatorIntExportField.php b/src/infrastructure/export/field/PhabricatorIntExportField.php
--- a/src/infrastructure/export/field/PhabricatorIntExportField.php
+++ b/src/infrastructure/export/field/PhabricatorIntExportField.php
@@ -12,10 +12,10 @@
   }
 
   /**
-   * @phutil-external-symbol class PHPExcel_Cell_DataType
+   * @phutil-external-symbol class \PhpOffice\PhpSpreadsheet\Cell\DataType
    */
   public function formatPHPExcelCell($cell, $style) {
-    $cell->setDataType(PHPExcel_Cell_DataType::TYPE_NUMERIC);
+    $cell->setDataType(\PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC);
   }
 
   public function getCharacterWidth() {
diff --git a/src/infrastructure/export/format/PhabricatorExcelExportFormat.php b/src/infrastructure/export/format/PhabricatorExcelExportFormat.php
--- a/src/infrastructure/export/format/PhabricatorExcelExportFormat.php
+++ b/src/infrastructure/export/format/PhabricatorExcelExportFormat.php
@@ -32,20 +32,20 @@
     }
 
     return pht(<<<EOHELP
-Data can not be exported to Excel because the PHPExcel library is not
+Data can not be exported to Excel because the PhpSpreadsheet library is not
 installed. This software component is required for Phabricator to create
 Excel files.
 
-You can install PHPExcel from GitHub:
+You can install PhpSpreadsheet from GitHub:
 
-> https://github.com/PHPOffice/PHPExcel
+> https://github.com/PHPOffice/PhpSpreadsheet/
 
 Briefly:
 
   - Clone that repository somewhere on the sever
-    (like `/path/to/example/PHPExcel`).
-  - Update your PHP `%s` setting (in `php.ini`) to include the PHPExcel
-    `Classes` directory (like `/path/to/example/PHPExcel/Classes`).
+    (like `/path/to/example/PhpSpreadsheet`).
+  - Update your PHP `%s` setting (in `php.ini`) to include the PhpSpreadsheet
+    `src` directory (like `/path/to/example/PhpSpreadsheet/src`).
 EOHELP
       ,
       'include_path');
@@ -60,7 +60,7 @@
   }
 
   /**
-   * @phutil-external-symbol class PHPExcel_Cell_DataType
+   * @phutil-external-symbol class \PhpOffice\PhpSpreadsheet\Cell\DataType
    */
   public function addHeaders(array $fields) {
     $sheet = $this->getSheet();
@@ -84,7 +84,7 @@
         $return_cell = true);
 
       $sheet->getStyle($cell_name)->applyFromArray($header_format);
-      $cell->setDataType(PHPExcel_Cell_DataType::TYPE_STRING);
+      $cell->setDataType(\PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING);
 
       $width = $field->getCharacterWidth();
       if ($width !== null) {