diff -r d94c4fd35c21 -r fdc2fb090cc7 libidav/session.c
--- a/libidav/session.c	Sat Oct 27 15:05:13 2018 +0200
+++ b/libidav/session.c	Sun Nov 04 16:35:44 2018 +0100
@@ -214,6 +214,7 @@
             case 405: sn->error = DAV_METHOD_NOT_ALLOWED; break;
             case 407: sn->error = DAV_PROXY_AUTH_REQUIRED; break;
             case 409: sn->error = DAV_CONFLICT; break;
+            case 412: sn->error = DAV_PRECONDITION_FAILED; break;
             case 413: sn->error = DAV_REQUEST_ENTITY_TOO_LARGE; break;
             case 414: sn->error = DAV_REQUEST_URL_TOO_LONG; break;
             case 423: sn->error = DAV_LOCKED; break;