diff --git a/inc/caldav-PUT-default.php b/inc/caldav-PUT-default.php
index 973501a2..4de93170 100644
--- a/inc/caldav-PUT-default.php
+++ b/inc/caldav-PUT-default.php
@@ -65,10 +65,11 @@ $collection_id = $container->GetProperty('collection_id');
 $qry = new AwlQuery();
 $qry->Begin();
 
+$etag = md5($request->raw_post);
 $params = array(
     ':user_no' => $dest->GetProperty('user_no'),
     ':dav_name' => $dest->bound_from(),
-    ':etag' => md5($request->raw_post),
+    ':etag' => $etag,
     ':dav_data' => $request->raw_post,
     ':session_user' => $session->user_no
 );
@@ -90,5 +91,6 @@ $qry->QDo("SELECT write_sync_change( $collection_id, $response_code, :dav_name)"
 $qry = new AwlQuery('COMMIT');
 if ( !$qry->Exec('move') ) rollback(500);
 
+header('ETag: "'. $etag . '"' );
 if ( $response_code == 200 ) $response_code = 204;
 $request->DoResponse( $response_code );
diff --git a/inc/caldav-PUT-vcard.php b/inc/caldav-PUT-vcard.php
index f8241f47..f7a14625 100644
--- a/inc/caldav-PUT-vcard.php
+++ b/inc/caldav-PUT-vcard.php
@@ -57,10 +57,11 @@ $collection_id = $container->GetProperty('collection_id');
 $qry = new AwlQuery();
 $qry->Begin();
 
+$etag = md5($request->raw_post);
 $params = array(
     ':user_no' => $dest->GetProperty('user_no'),
     ':dav_name' => $dest->bound_from(),
-    ':etag' => md5($request->raw_post),
+    ':etag' => $etag,
     ':dav_data' => $request->raw_post,
     ':session_user' => $session->user_no
 );
@@ -92,5 +93,6 @@ $qry->QDo("SELECT write_sync_change( $collection_id, $response_code, :dav_name)"
 
 if ( !$qry->QDo('COMMIT') ) rollback(500);
 
+header('ETag: "'. $etag . '"' );
 if ( $response_code == 200 ) $response_code = 204;
 $request->DoResponse( $response_code );
diff --git a/testing/tests/carddav/2003-PUT-vcard.result b/testing/tests/carddav/2003-PUT-vcard.result
index 7999f41b..3c61c942 100644
--- a/testing/tests/carddav/2003-PUT-vcard.result
+++ b/testing/tests/carddav/2003-PUT-vcard.result
@@ -4,6 +4,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "24bae2a7f81c0a79413a656c06d8326b"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2006-PUT-vcard.result b/testing/tests/carddav/2006-PUT-vcard.result
index 142a26f4..f03543a2 100644
--- a/testing/tests/carddav/2006-PUT-vcard.result
+++ b/testing/tests/carddav/2006-PUT-vcard.result
@@ -2,6 +2,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "fada70a725708bce8521efb87acfa629"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2013-PUT-vcard.result b/testing/tests/carddav/2013-PUT-vcard.result
index debc0931..d4bae00c 100644
--- a/testing/tests/carddav/2013-PUT-vcard.result
+++ b/testing/tests/carddav/2013-PUT-vcard.result
@@ -2,6 +2,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "3419498c6e5eae71dc1704f1787faf1c"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2014-PUT-vcard.result b/testing/tests/carddav/2014-PUT-vcard.result
index bf79db96..4a609cdd 100644
--- a/testing/tests/carddav/2014-PUT-vcard.result
+++ b/testing/tests/carddav/2014-PUT-vcard.result
@@ -4,6 +4,7 @@ HTTP/1.1 204 No Content
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "0ea4d7759e103090c6494505b5da0f11"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2015-PUT-vcard.result b/testing/tests/carddav/2015-PUT-vcard.result
index f88848b9..52e628d7 100644
--- a/testing/tests/carddav/2015-PUT-vcard.result
+++ b/testing/tests/carddav/2015-PUT-vcard.result
@@ -2,6 +2,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "d43780719361367f2d690f1f966e3da1"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2016-PUT-vcard.result b/testing/tests/carddav/2016-PUT-vcard.result
index 1e2a67cc..05fd4796 100644
--- a/testing/tests/carddav/2016-PUT-vcard.result
+++ b/testing/tests/carddav/2016-PUT-vcard.result
@@ -4,6 +4,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "e67537e9d473e93911eccd6e63e9ac3a"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2017-PUT-vcard.result b/testing/tests/carddav/2017-PUT-vcard.result
index 7a07d35d..c9c7c7c0 100644
--- a/testing/tests/carddav/2017-PUT-vcard.result
+++ b/testing/tests/carddav/2017-PUT-vcard.result
@@ -4,6 +4,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "f6ae02ec1b5612fe4737092734d062c7"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2018-PUT-vcard.result b/testing/tests/carddav/2018-PUT-vcard.result
index a1e155ad..aebe6a72 100644
--- a/testing/tests/carddav/2018-PUT-vcard.result
+++ b/testing/tests/carddav/2018-PUT-vcard.result
@@ -4,6 +4,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "db3e92c0ae37268c647949367e2030cc"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2019-PUT-vcard.result b/testing/tests/carddav/2019-PUT-vcard.result
index 9e2ba352..4a565537 100644
--- a/testing/tests/carddav/2019-PUT-vcard.result
+++ b/testing/tests/carddav/2019-PUT-vcard.result
@@ -2,6 +2,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "feaa1a28c9942fc56403e2f97f75171b"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"
 
diff --git a/testing/tests/carddav/2020-PUT-vcard.result b/testing/tests/carddav/2020-PUT-vcard.result
index 21da431f..516b8de6 100644
--- a/testing/tests/carddav/2020-PUT-vcard.result
+++ b/testing/tests/carddav/2020-PUT-vcard.result
@@ -2,6 +2,7 @@ HTTP/1.1 201 Created
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, calendar-proxy, bind, addressbook, calendar-auto-schedule
+ETag: "5a32961b9938a7d6a354a757a8a1ea36"
 Content-Length: 0
 Content-Type: text/plain; charset="utf-8"