diff --git a/Web/Models/Repositories/ChandlerGroups.php b/Web/Models/Repositories/ChandlerGroups.php
index 45af2a62..30b706e2 100644
--- a/Web/Models/Repositories/ChandlerGroups.php
+++ b/Web/Models/Repositories/ChandlerGroups.php
@@ -45,4 +45,9 @@ class ChandlerGroups
     {
         foreach($this->perms->where("group", $UUID) as $perm) yield $perm;
     }
+
+    function isUserAMember(string $GID, string $UID): bool
+    {
+        return ($this->context->query("SELECT * FROM `ChandlerACLRelations` WHERE `group` = ? AND `user` = ?", $GID, $UID)) !== NULL;
+    }
 }
diff --git a/Web/Presenters/AdminPresenter.php b/Web/Presenters/AdminPresenter.php
index 658d2f4b..3d864e56 100644
--- a/Web/Presenters/AdminPresenter.php
+++ b/Web/Presenters/AdminPresenter.php
@@ -110,8 +110,10 @@ final class AdminPresenter extends OpenVKPresenter
                 if($user->onlineStatus() != $this->postParam("online")) $user->setOnline(intval($this->postParam("online")));
                 $user->setVerified(empty($this->postParam("verify") ? 0 : 1));
                 if($this->postParam("add-to-group")) {
-                    $query = "INSERT INTO `ChandlerACLRelations` (`user`, `group`) VALUES ('" . $user->getChandlerGUID() . "', '" . $this->postParam("add-to-group") . "')";
-                    DatabaseConnection::i()->getConnection()->query($query);
+                    if (!(new ChandlerGroups)->isUserAMember($user->getChandlerGUID(), $this->postParam("add-to-group"))) {
+                        $query = "INSERT INTO `ChandlerACLRelations` (`user`, `group`) VALUES ('" . $user->getChandlerGUID() . "', '" . $this->postParam("add-to-group") . "')";
+                        DatabaseConnection::i()->getConnection()->query($query);
+                    }
                 }
                 if($this->postParam("password")) {
                     $user->getChandlerUser()->updatePassword($this->postParam("password"));