diff --git a/php/makeOrbitsInKm.php b/php/makeOrbitsInKm.php
index 0da24c1..f1a0c07 100644
--- a/php/makeOrbitsInKm.php
+++ b/php/makeOrbitsInKm.php
@@ -72,7 +72,7 @@
 					$newInfo->addChild('short_name', $paramXml->info->name);
 					$newInfo->addChild('components', $paramXml->info->components);
 					$newInfo->addChild('units', 'km');
-					$newInfo->addChild('coordinates_system', $paramXml->info->coordinates_system);
+					$newInfo->addChild('coordinate_system', $paramXml->info->coordinates_system);
 					$newInfo->addChild('tensor_order', $paramXml->info->tensor_order);
 					$newInfo->addChild('si_conversion', 1.e3);
 					//TODO scale fill value
--
libgit2 0.21.2