diff --git a/src/_h5ai/server/php/inc/Archive.php b/src/_h5ai/server/php/inc/Archive.php
index adc1d263..5efb6fd6 100644
--- a/src/_h5ai/server/php/inc/Archive.php
+++ b/src/_h5ai/server/php/inc/Archive.php
@@ -57,7 +57,7 @@ class Archive {
 		try {
 
 			if ($format === "tar") {
-				return $this->create_tar();
+				$cmd = Archive::$TAR_PASSTHRU_CMD;
 			} else if ($format === "zip") {
 				$cmd = Archive::$ZIP_PASSTHRU_CMD;
 			} else {