diff --git a/inc/caldav-REPORT-sync-collection.php b/inc/caldav-REPORT-sync-collection.php
index be6fbeb0..50da1d60 100644
--- a/inc/caldav-REPORT-sync-collection.php
+++ b/inc/caldav-REPORT-sync-collection.php
@@ -17,7 +17,7 @@ $responses = array();
 $sync_tokens = $xmltree->GetPath('/DAV::sync-collection/DAV::sync-token');
 $sync_token = $sync_tokens[0]->GetContent();
 if ( !isset($sync_token) ) $sync_token = 0;
-$sync_token = intval($sync_token);
+$sync_token = intval(str_ireplace('data:,', '', $sync_token ));
 dbg_error_log( 'sync', " sync-token: %s", $sync_token );
 
 
@@ -59,7 +59,7 @@ $new_token = $row->new_sync_token;
 
 if ( $sync_token == $new_token ) {
   // No change, so we just re-send the old token.
-  $responses[] = new XMLElement( 'sync-token', $new_token );
+  $responses[] = new XMLElement( 'sync-token', 'data:,'.$new_token );
 }
 else {
   if ( $sync_token == 0 ) {
@@ -142,7 +142,7 @@ EOSQL;
         $last_dav_name  = $object->dav_name;
       }
     }
-    $responses[] = new XMLElement( 'sync-token', $new_token );
+    $responses[] = new XMLElement( 'sync-token', 'data:,'.$new_token );
   }
   else {
     $request->DoResponse( 500, translate("Database error") );
diff --git a/testing/tests/binding/1036-REPORT-sync-initial-bound.result b/testing/tests/binding/1036-REPORT-sync-initial-bound.result
index 8d1ad028..84fa0969 100644
--- a/testing/tests/binding/1036-REPORT-sync-initial-bound.result
+++ b/testing/tests/binding/1036-REPORT-sync-initial-bound.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "53ade6e4324c9f7e2060a4e760bda6f5"
-Content-Length: 2286
+ETag: "f7758fc9ba3182e47aba690683524e55"
+Content-Length: 2292
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -89,5 +89,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>5</sync-token>
+ <sync-token>data:,5</sync-token>
 </multistatus>
diff --git a/testing/tests/carddav/2010-REPORT-sync-initial.result b/testing/tests/carddav/2010-REPORT-sync-initial.result
index dfc48083..cef5dd00 100644
--- a/testing/tests/carddav/2010-REPORT-sync-initial.result
+++ b/testing/tests/carddav/2010-REPORT-sync-initial.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "c07ace186b168e6268fce37c17ae7896"
-Content-Length: 942
+ETag: "3446b8401735be64ec24b3e1af5362db"
+Content-Length: 948
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -38,5 +38,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>6</sync-token>
+ <sync-token>data:,6</sync-token>
 </multistatus>
diff --git a/testing/tests/carddav/2039-REPORT-sync-changed.result b/testing/tests/carddav/2039-REPORT-sync-changed.result
index dd3bd372..af80f2b5 100644
--- a/testing/tests/carddav/2039-REPORT-sync-changed.result
+++ b/testing/tests/carddav/2039-REPORT-sync-changed.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "246e590e6b688fd0a7b2397368de6b52"
-Content-Length: 1788
+ETag: "f0c7bfe2540087faa968b4a4321f8953"
+Content-Length: 1794
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -71,5 +71,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>7</sync-token>
+ <sync-token>data:,7</sync-token>
 </multistatus>
diff --git a/testing/tests/regression-suite/0099-REPORT-sync-initial.result b/testing/tests/regression-suite/0099-REPORT-sync-initial.result
index 107d9e51..2fa7b865 100644
--- a/testing/tests/regression-suite/0099-REPORT-sync-initial.result
+++ b/testing/tests/regression-suite/0099-REPORT-sync-initial.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "68077b6249044e2937b6d0119c0eb656"
-Content-Length: 354
+ETag: "428b3b0b0de29ffd0f827a6a9d36ab26"
+Content-Length: 360
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -17,5 +17,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>1</sync-token>
+ <sync-token>data:,1</sync-token>
 </multistatus>
diff --git a/testing/tests/regression-suite/0598-REPORT-sync-initial.result b/testing/tests/regression-suite/0598-REPORT-sync-initial.result
index 4740a731..4da26c6d 100644
--- a/testing/tests/regression-suite/0598-REPORT-sync-initial.result
+++ b/testing/tests/regression-suite/0598-REPORT-sync-initial.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "745883b4e0a01c261f2ae80105258a14"
-Content-Length: 4024
+ETag: "4455c8df8e5a0572ba52dccb00843cfe"
+Content-Length: 4030
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -152,5 +152,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>2</sync-token>
+ <sync-token>data:,2</sync-token>
 </multistatus>
diff --git a/testing/tests/regression-suite/0599-REPORT-sync-changed.result b/testing/tests/regression-suite/0599-REPORT-sync-changed.result
index 654d0f42..874767f9 100644
--- a/testing/tests/regression-suite/0599-REPORT-sync-changed.result
+++ b/testing/tests/regression-suite/0599-REPORT-sync-changed.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "41c9017eda1f4a021c881f217b97407a"
-Content-Length: 3780
+ETag: "a4ec15e128c8e06e81c57af754448f81"
+Content-Length: 3786
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -143,5 +143,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>3</sync-token>
+ <sync-token>data:,3</sync-token>
 </multistatus>
diff --git a/testing/tests/regression-suite/1100-REPORT-sync-changed.result b/testing/tests/regression-suite/1100-REPORT-sync-changed.result
index 3e559563..ff223a4c 100644
--- a/testing/tests/regression-suite/1100-REPORT-sync-changed.result
+++ b/testing/tests/regression-suite/1100-REPORT-sync-changed.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 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: "f1d7fb1befbea4830cd1afc134974fc4"
-Content-Length: 5873
+ETag: "40e69ecd1e31ae458e1fa4505c1ee585"
+Content-Length: 5879
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -192,5 +192,5 @@ Content-Type: text/xml; charset="utf-8"
    <status>HTTP/1.1 200 OK</status>
   </propstat>
  </response>
- <sync-token>4</sync-token>
+ <sync-token>data:,4</sync-token>
 </multistatus>