diff --git a/classes/DataWarehouse/Export/FileManager.php b/classes/DataWarehouse/Export/FileManager.php
index f7e11c8636..adee61ced0 100644
--- a/classes/DataWarehouse/Export/FileManager.php
+++ b/classes/DataWarehouse/Export/FileManager.php
@@ -252,9 +252,8 @@ public function createZipFile($dataFile, array $request)
                 ));
             }
 
-            if (!$zip->addFromString('README.txt',
-                $this->getReadmeText($request['realm']))
-            ) {
+            $readmeText = $this->getReadmeText($request['realm']);
+            if (!$zip->addFromString('README.txt', $readmeText)) {
                 throw new Exception(sprintf(
                     'Failed to add "README.txt" to zip file "%s"',
                     $dataFile,