diff --git a/core/js/setupchecks.js b/core/js/setupchecks.js
index f9829954f1..1e50644aa2 100644
--- a/core/js/setupchecks.js
+++ b/core/js/setupchecks.js
@@ -40,6 +40,7 @@
 						'<d:propfind xmlns:d="DAV:">' +
 						'<d:prop><d:resourcetype/></d:prop>' +
 						'</d:propfind>',
+				contentType: 'application/xml; charset=utf-8',
 				complete: afterCall,
 				allowAuthErrors: true
 			});