diff -urN ../z-push-2.6.4+0.orig/src/lib/syncobjects/syncobject.php ./src/lib/syncobjects/syncobject.php
--- ../z-push-2.6.4+0.orig/src/lib/syncobjects/syncobject.php	2021-06-25 11:55:30.000000000 +0300
+++ ./src/lib/syncobjects/syncobject.php	2023-06-11 20:09:13.372164000 +0300
@@ -528,6 +528,7 @@
                                 ZLog::Write(LOGLEVEL_WARN, sprintf("SyncObject->Check(): Unmet condition in object from type %s: parameter '%s' can not be compared, as the comparable is not set. Check failed!", $objClass, $v[self::STREAMER_VAR]));
                                 return false;
                             }
+                            if (is_int($this->{$v[self::STREAMER_VAR]}))
                             if ( ($rule == self::STREAMER_CHECK_CMPHIGHER && $this->{$v[self::STREAMER_VAR]} < $cmp) ||
                                  ($rule == self::STREAMER_CHECK_CMPLOWER  && $this->{$v[self::STREAMER_VAR]} > $cmp)
                                 ) {