diff --git a/usr/local/www/system_firmware.php b/usr/local/www/system_firmware.php
index 151ce2868e..45dd6fced2 100755
--- a/usr/local/www/system_firmware.php
+++ b/usr/local/www/system_firmware.php
@@ -137,9 +137,9 @@ if ($_POST && !file_exists($d_firmwarelock_path)) {
                             /* fire up the update script in the background */
                             touch($d_firmwarelock_path);
                             $savemsg = "The firmware is now being updated. The firewall will reboot automatically.";
-							if(stristr($_FILES['ulfile']['tmp_name'],"nanobsd"))
+							if(stristr($_FILES['ulfile']['name'],"nanobsd"))
 								mwexec_bg("/etc/rc.firmware pfSenseNanoBSDupgrade {$g['upload_path']}/firmware.tgz");
-							else if(stristr($_FILES['ulfile']['tmp_name'],"bdiff"))
+							else if(stristr($_FILES['ulfile']['name'],"bdiff"))
                             	mwexec_bg("/etc/rc.firmware delta_update {$g['upload_path']}/firmware.tgz");
 							else 
 								mwexec_bg("/etc/rc.firmware pfSenseupgrade {$g['upload_path']}/firmware.tgz");