diff --git a/apps/contacts/ajax/categories/list.php b/apps/contacts/ajax/categories/list.php
index 3b41b7bfa9..64d74c82e6 100644
--- a/apps/contacts/ajax/categories/list.php
+++ b/apps/contacts/ajax/categories/list.php
@@ -10,7 +10,7 @@ require_once('../../../../lib/base.php');
 OC_JSON::checkLoggedIn();
 OC_JSON::checkAppEnabled('contacts');
 
-$categories = OC_Contacts_App::$categories->categories();
+$categories = OC_Contacts_App::getCategories();
 
 OC_JSON::success(array('data' => array('categories'=>$categories)));
 
diff --git a/apps/contacts/ajax/categories/rescan.php b/apps/contacts/ajax/categories/rescan.php
index dd27192baa..5f1057bab4 100644
--- a/apps/contacts/ajax/categories/rescan.php
+++ b/apps/contacts/ajax/categories/rescan.php
@@ -36,13 +36,8 @@ if(count($contacts) == 0) {
 	bailOut(OC_Contacts_App::$l10n->t('No contacts found.'));
 }
 
-$cards = array();
-foreach($contacts as $contact) {
-	$cards[] = $contact['carddata'];
-} 
-
-OC_Contacts_App::$categories->rescan($cards);
-$categories = OC_Contacts_App::$categories->categories();
+OC_Contacts_App::scanCategories($contacts);
+$categories = OC_Contacts_App::getCategories();
 
 OC_JSON::success(array('data' => array('categories'=>$categories)));
 
diff --git a/apps/contacts/index.php b/apps/contacts/index.php
index 776c57ca60..97117c329b 100644
--- a/apps/contacts/index.php
+++ b/apps/contacts/index.php
@@ -35,25 +35,6 @@ if(!is_null($id)) {
 $property_types = OC_Contacts_App::getAddPropertyOptions();
 $phone_types = OC_Contacts_App::getTypesOfProperty('TEL');
 $categories = OC_Contacts_App::getCategories();
-if(count($categories) == 0) {
-	$vcaddressbooks = OC_Contacts_Addressbook::all(OC_User::getUser());
-	if(count($vcaddressbooks) > 0) {
-		$vcaddressbookids = array();
-		foreach($vcaddressbooks as $vcaddressbook) {
-			$vcaddressbookids[] = $vcaddressbook['id'];
-		} 
-		$vccontacts = OC_Contacts_VCard::all($vcaddressbookids);
-		if(count($vccontacts) > 0) {
-			$cards = array();
-			foreach($vccontacts as $vccontact) {
-				$cards[] = $vccontact['carddata'];
-			} 
-
-			OC_Contacts_App::$categories->rescan($cards);
-			$categories = OC_Contacts_App::$categories->categories();
-		}
-	}
-}
 
 $upload_max_filesize = OC_Helper::computerFileSize(ini_get('upload_max_filesize'));
 $post_max_size = OC_Helper::computerFileSize(ini_get('post_max_size'));
diff --git a/apps/contacts/lib/app.php b/apps/contacts/lib/app.php
index cc33c73300..f6f6e61907 100644
--- a/apps/contacts/lib/app.php
+++ b/apps/contacts/lib/app.php
@@ -156,7 +156,45 @@ class OC_Contacts_App {
 	}
 
 	public static function getCategories() {
-		return self::$categories->categories();
+		$categories = self::$categories->categories();
+		if(count($categories) == 0) {
+			self::scanCategories();
+			$categories = self::$categories->categories();
+		}
+		return $categories;
+	}
+
+	/**
+	 * scan vcards for categories.
+	 * @param $vccontacts VCards to scan. null to check all vcards for the current user.
+	 */
+	public static function scanCategories($vccontacts = null) {
+		if (is_null($vccontacts)) {
+			$vcaddressbooks = OC_Contacts_Addressbook::all(OC_User::getUser());
+			if(count($vcaddressbooks) > 0) {
+				$vcaddressbookids = array();
+				foreach($vcaddressbooks as $vcaddressbook) {
+					$vcaddressbookids[] = $vcaddressbook['id'];
+				}
+				$vccontacts = OC_Contacts_VCard::all($vcaddressbookids);
+			}
+		}
+		if(is_array($vccontacts) && count($vccontacts) > 0) {
+			$cards = array();
+			foreach($vccontacts as $vccontact) {
+				$cards[] = $vccontact['carddata'];
+			}
+
+			self::$categories->rescan($cards);
+		}
+	}
+
+	/**
+	 * check VCard for new categories.
+	 * @see OC_VCategories::loadFromVObject
+	 */
+	public static function loadCategoriesFromVCard(OC_VObject $contact) {
+		self::$categories->loadFromVObject($contact);
 	}
 
 	public static function setLastModifiedHeader($contact) {
diff --git a/apps/contacts/lib/vcard.php b/apps/contacts/lib/vcard.php
index 15a6176d40..1502423b90 100644
--- a/apps/contacts/lib/vcard.php
+++ b/apps/contacts/lib/vcard.php
@@ -234,7 +234,7 @@ class OC_Contacts_VCard{
 			return null;
 		};
 
-		OC_Contacts_App::$categories->loadFromVObject($card);
+		OC_Contacts_App::loadCategoriesFromVCard($card);
 
 		self::updateValuesFromAdd($card);
 
@@ -306,7 +306,7 @@ class OC_Contacts_VCard{
 			return false;
 		}
 
-		OC_Contacts_App::$categories->loadFromVObject($card);
+		OC_Contacts_App::loadCategoriesFromVCard($card);
 
 		$fn = $card->getAsString('FN');
 		if (empty($fn)) {