diff --git a/library/Director/Import/Sync.php b/library/Director/Import/Sync.php
index ae42789e..c29298a1 100644
--- a/library/Director/Import/Sync.php
+++ b/library/Director/Import/Sync.php
@@ -6,6 +6,9 @@ use Exception;
 use Icinga\Data\Filter\Filter;
 use Icinga\Module\Director\Db;
 use Icinga\Module\Director\Db\Cache\PrefetchCache;
+use Icinga\Module\Director\Objects\HostGroupMembershipResolver;
+use Icinga\Module\Director\Objects\IcingaHost;
+use Icinga\Module\Director\Objects\IcingaHostGroup;
 use Icinga\Module\Director\Objects\IcingaObject;
 use Icinga\Module\Director\Objects\ImportSource;
 use Icinga\Module\Director\Objects\IcingaService;
@@ -79,6 +82,9 @@ class Sync
     /** @var Filter[] */
     protected $columnFilters = array();
 
+    /** @var HostGroupMembershipResolver|bool */
+    protected $hostGropMembershipResolver;
+
     /**
      * Constructor. No direct initialization allowed right now. Please use one
      * of the available static factory methods
@@ -480,6 +486,53 @@ class Sync
         return $newObjects;
     }
 
+    protected function deferResolvers()
+    {
+        if (in_array($this->rule->get('object_type'), array('host', 'hostgroup'))) {
+            $resolver = new HostGroupMembershipResolver($this->db);
+            $resolver->defer()->setUseTransactions(false);
+        }
+
+        return $this;
+    }
+
+    protected function setResolver(IcingaObject $object)
+    {
+        if ($resolver = $this->getHostGropMembershipResolver()) {
+            /** @var IcingaHost|IcingaHostGroup $object */
+            $object->setHostGroupMembershipResolver($resolver);
+        }
+
+        return $this;
+    }
+
+    protected function notifyResolvers()
+    {
+        if ($resolver = $this->getHostGropMembershipResolver()) {
+            $resolver->defer();
+        }
+
+        return $this;
+    }
+
+    protected function getHostGropMembershipResolver()
+    {
+        if ($this->hostGropMembershipResolver === null) {
+            if (in_array(
+                $this->rule->get('object_type'),
+                array('host', 'hostgroup')
+            )) {
+                $this->hostGropMembershipResolver = new HostGroupMembershipResolver(
+                    $this->db
+                );
+            } else {
+                $this->hostGropMembershipResolver = false;
+            }
+        }
+
+        return $this->hostGropMembershipResolver;
+    }
+
     /**
      * Evaluates a SyncRule and returns a list of modified objects
      *
@@ -501,7 +554,8 @@ class Sync
              ->prepareRelatedImportSources()
              ->prepareSourceColumns()
              ->loadExistingObjects()
-             ->fetchImportedData();
+             ->fetchImportedData()
+             ->deferResolvers();
 
         // TODO: directly work on existing objects, remember imported keys, then purge
         $newObjects = $this->prepareNewObjects();
@@ -579,6 +633,7 @@ class Sync
             $modified = 0;
             $deleted = 0;
             foreach ($objects as $object) {
+                $this->setResolver($object);
                 if ($object->shouldBeRemoved()) {
                     $object->delete($db);
                     $deleted++;
diff --git a/library/Director/Objects/HostGroupMembershipResolver.php b/library/Director/Objects/HostGroupMembershipResolver.php
index a3c6f456..0e98d9e0 100644
--- a/library/Director/Objects/HostGroupMembershipResolver.php
+++ b/library/Director/Objects/HostGroupMembershipResolver.php
@@ -32,12 +32,16 @@ class HostGroupMembershipResolver
     /** @var IcingaHost[] */
     protected $hosts;
 
-    /** @var IcingaHostGroup */
+    /** @var IcingaHostGroup[] */
     protected $hostgroups = array();
 
     protected $table = 'icinga_hostgroup_host_resolved';
 
-    protected static $deferred;
+    /** @var bool */
+    protected $deferred = false;
+
+    /** @var bool */
+    protected $useTransactions = false;
 
     public function __construct(Db $connection)
     {
@@ -59,7 +63,7 @@ class HostGroupMembershipResolver
      */
     public function refreshDb($force = false)
     {
-        if ($force || ! static::$deferred) {
+        if ($force || ! $this->isDeferred()) {
             Benchmark::measure('Going to refresh all hostgroup mappings');
             $this->fetchStoredMappings();
             Benchmark::measure('Got stored HG mappings, rechecking all hosts');
@@ -72,14 +76,32 @@ class HostGroupMembershipResolver
         return $this;
     }
 
-    public static function defer($defer = true)
+    /**
+     * @param bool $defer
+     * @return $this
+     */
+    public function defer($defer = true)
     {
-        static::$deferred = $defer;
+        $this->deferred = $defer;
+        return $this;
     }
 
-    public static function isDeferred()
+    /**
+     * @param $use
+     * @return $this
+     */
+    public function setUseTransactions($use)
     {
-        return static::$deferred;
+        $this->useTransactions = $use;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isDeferred()
+    {
+        return $this->deferred;
     }
 
     /**
@@ -205,7 +227,7 @@ class HostGroupMembershipResolver
         }
 
         $db = $this->db;
-        $db->beginTransaction();
+        $this->beginTransaction();
         foreach ($diff as $row) {
             $db->insert(
                 $this->table,
@@ -213,7 +235,7 @@ class HostGroupMembershipResolver
             );
         }
 
-        $db->commit();
+        $this->commit();
         Benchmark::measure(
             sprintf(
                 'Stored %d new resolved hostgroup memberships',
@@ -231,7 +253,7 @@ class HostGroupMembershipResolver
         }
 
         $db = $this->db;
-        $db->beginTransaction();
+        $this->beginTransaction();
         foreach ($diff as $row) {
             $db->delete(
                 $this->table,
@@ -243,7 +265,7 @@ class HostGroupMembershipResolver
             );
         }
 
-        $db->commit();
+        $this->commit();
         Benchmark::measure(
             sprintf(
                 'Removed %d outdated hostgroup memberships',
@@ -306,6 +328,12 @@ class HostGroupMembershipResolver
         $this->existingMappings = $mappings;
     }
 
+    /**
+     * @param ZfSelect $query
+     * @param string $column
+     * @param IcingaObject[] $objects
+     * @return ZfSelect
+     */
     protected function addMembershipWhere(ZfSelect $query, $column, & $objects)
     {
         if (empty($objects)) {
@@ -379,6 +407,30 @@ class HostGroupMembershipResolver
         return $this->db->fetchPairs($query);
     }
 
+    /**
+     * @return $this
+     */
+    protected function beginTransaction()
+    {
+        if ($this->useTransactions) {
+            $this->db->beginTransaction();
+        }
+
+        return $this;
+    }
+
+    /**
+     * @return $this
+     */
+    protected function commit()
+    {
+        if ($this->useTransactions) {
+            $this->db->commit();
+        }
+
+        return $this;
+    }
+
     /**
      * @return IcingaHost[]
      */
@@ -393,7 +445,7 @@ class HostGroupMembershipResolver
 
     protected function assertBeenLoadedFromDb(IcingaObject $object)
     {
-        if (! $object->hasBeenLoadedFromDb()) {
+        if (! ctype_digit($object->get('id'))) {
             throw new ProgrammingError(
                 'Hostgroup resolver does not support unstored objects'
             );
diff --git a/library/Director/Objects/IcingaHost.php b/library/Director/Objects/IcingaHost.php
index 532a3480..2e43ab20 100644
--- a/library/Director/Objects/IcingaHost.php
+++ b/library/Director/Objects/IcingaHost.php
@@ -315,6 +315,12 @@ class IcingaHost extends IcingaObject
         return $this->hostgroupMembershipResolver;
     }
 
+    public function setHostGroupMembershipResolver(HostGroupMembershipResolver $resolver)
+    {
+        $this->hostgroupMembershipResolver = $resolver;
+        return $this;
+    }
+
     protected function getServiceOverrivesVarname()
     {
         return $this->connection->settings()->override_services_varname;
diff --git a/library/Director/Objects/IcingaHostGroup.php b/library/Director/Objects/IcingaHostGroup.php
index 026ff966..0d1ec0e0 100644
--- a/library/Director/Objects/IcingaHostGroup.php
+++ b/library/Director/Objects/IcingaHostGroup.php
@@ -39,6 +39,12 @@ class IcingaHostGroup extends IcingaObjectGroup
         return $this->hostgroupMembershipResolver;
     }
 
+    public function setHostGroupMembershipResolver(HostGroupMembershipResolver $resolver)
+    {
+        $this->hostgroupMembershipResolver = $resolver;
+        return $this;
+    }
+
     protected function notifyResolvers()
     {
         $resolver = $this->getHostGroupMembershipResolver();
diff --git a/library/Director/Objects/IcingaObject.php b/library/Director/Objects/IcingaObject.php
index b645ad08..067ea92a 100644
--- a/library/Director/Objects/IcingaObject.php
+++ b/library/Director/Objects/IcingaObject.php
@@ -1278,8 +1278,7 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
             ->storeImports()
             ->storeRanges()
             ->storeRelatedSets()
-            ->storeArguments()
-            ->notifyResolvers();
+            ->storeArguments();
     }
 
     protected function beforeStore()
@@ -1299,6 +1298,11 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
         $this->storeRelatedObjects();
     }
 
+    public function onStore()
+    {
+        $this->notifyResolvers();
+    }
+
     /**
      * @return self
      */