diff --git a/src/EntityMap.php b/src/EntityMap.php
index f98b246..6098827 100755
--- a/src/EntityMap.php
+++ b/src/EntityMap.php
@@ -481,7 +481,9 @@ public function getEmbeddables(): array
      */
     public function getProperties(): array
     {
-        return $this->properties;
+        return get_parent_class(__CLASS__) !== false
+            ? array_unique(array_merge($this->properties, parent::getProperties()))
+            : $this->properties;
     }
 
     /**
diff --git a/src/System/Proxies/CollectionProxy.php b/src/System/Proxies/CollectionProxy.php
index 8b74735..7f0abd0 100644
--- a/src/System/Proxies/CollectionProxy.php
+++ b/src/System/Proxies/CollectionProxy.php
@@ -3,6 +3,7 @@
 namespace Analogue\ORM\System\Proxies;
 
 use Analogue\ORM\EntityCollection;
+use Analogue\ORM\Relationships\Relationship;
 use Analogue\ORM\System\Manager;
 use CachingIterator;
 use Illuminate\Support\Collection;
@@ -73,18 +74,28 @@ public function initializeProxy() : bool
             return true;
         }
 
-        $relation = $this->relationshipMethod;
-        $entity = $this->parentEntity;
-
-        $entityMap = Manager::getMapper($entity)->getEntityMap();
-
-        $this->items = $entityMap->$relation($entity)->getResults($relation)->all() + $this->addedItems;
+        $this->items = $this->getRelationshipInstance()
+            ->getResults($this->relationshipMethod)->all() + $this->addedItems;
 
         $this->relationshipLoaded = true;
 
         return true;
     }
 
+    /**
+     * Return instance of the underlying relationship.
+     *
+     * @return Relationship
+     */
+    protected function getRelationshipInstance() : Relationship
+    {
+        $relation = $this->relationshipMethod;
+        $entity = $this->parentEntity;
+        $entityMap = Manager::getMapper($entity)->getEntityMap();
+
+        return $entityMap->$relation($entity);
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -187,6 +198,18 @@ public function diff($items)
         return $parent->diff($items);
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function diffUsing($items, callable $callback)
+    {
+        $this->initializeProxy();
+
+        $parent = $this->toBaseCollection();
+
+        return $parent->diff($items, $callback);
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -1109,10 +1132,19 @@ public function getCachingIterator($flags = CachingIterator::CALL_TOSTRING)
      */
     public function count()
     {
-        // TODO rely on QB if not initialized
-        $this->initializeProxy();
+        return $this->relationshipLoaded
+            ? parent::count()
+            : $this->countUsingDatabaseQuery();
+    }
 
-        return parent::count();
+    /**
+     * Do a count query and return the result.
+     *
+     * @return int
+     */
+    protected function countUsingDatabaseQuery() : int
+    {
+        return $this->getRelationshipInstance()->count();
     }
 
     /**
diff --git a/tests/cases/CollectionProxyTest.php b/tests/cases/CollectionProxyTest.php
index 2f3b957..528100f 100644
--- a/tests/cases/CollectionProxyTest.php
+++ b/tests/cases/CollectionProxyTest.php
@@ -1,8 +1,8 @@
 <?php
 
-
 use Analogue\ORM\System\Proxies\CollectionProxy;
 use Illuminate\Support\Collection;
+use TestApp\User;
 
 class CollectionProxyTest extends DomainTestCase
 {
@@ -57,6 +57,18 @@ public function all_collection_methods_are_overloaded()
         $this->assertTrue(true);
     }
 
+    /** @test */
+    public function we_can_do_a_count_operation_on_proxy_without_loading_it()
+    {
+        $id = $this->createRelatedSet(3);
+        $user = mapper(User::class)->find($id);
+        $this->assertFalse($user->groups->isProxyInitialized());
+        $this->assertEquals(3, $user->groups->count());
+        $this->assertFalse($user->groups->isProxyInitialized());
+        $this->assertCount(3, $user->groups->all());
+        $this->assertTrue($user->groups->isProxyInitialized());
+    }
+
     /** @test */
     public function we_can_push_to_a_collection_proxy_without_loading_it()
     {
@@ -66,4 +78,26 @@ public function we_can_push_to_a_collection_proxy_without_loading_it()
     public function we_can_remove_from_a_lazy_collection_without_loading_it()
     {
     }
+
+    /**
+     * Create a random related set.
+     *
+     * @return int
+     */
+    protected function createRelatedSet($relatedCount = 1)
+    {
+        $userId = $this->insertUser();
+        for ($x = 1; $x <= $relatedCount; $x++) {
+            $groupId = $this->rawInsert('groups', [
+                'id'   => $this->randId(),
+                'name' => $this->faker()->sentence,
+            ]);
+            $this->rawInsert('groups_users', [
+                'user_id'  => $userId,
+                'group_id' => $groupId,
+            ]);
+        }
+
+        return $userId;
+    }
 }