diff --git a/plugins/libcalendaring/libvcalendar.php b/plugins/libcalendaring/libvcalendar.php
index a45da6e2..3cb7826f 100644
--- a/plugins/libcalendaring/libvcalendar.php
+++ b/plugins/libcalendaring/libvcalendar.php
@@ -471,7 +471,7 @@ class libvcalendar implements Iterator
 
             case 'CATEGORY':
             case 'CATEGORIES':
-                $event['categories'] = $prop->getParts();
+                $event['categories'] = array_merge((array)$event['categories'], $prop->getParts());
                 break;
 
             case 'CLASS':
diff --git a/plugins/libcalendaring/tests/libvcalendar.php b/plugins/libcalendaring/tests/libvcalendar.php
index f5c61f91..aa2c5680 100644
--- a/plugins/libcalendaring/tests/libvcalendar.php
+++ b/plugins/libcalendaring/tests/libvcalendar.php
@@ -321,6 +321,7 @@ class libvcalendar_test extends PHPUnit_Framework_TestCase
         $this->assertEquals('-1D:DISPLAY',  $task['alarms'],  "Taks alarm value");
         $this->assertEquals('IN-PROCESS',   $task['status'],  "Task status property");
         $this->assertEquals(1, count($task['x-custom']),      "Custom properties");
+        $this->assertEquals(4, count($task['categories']));
     }
 
     /**
diff --git a/plugins/libcalendaring/tests/resources/vtodo.ics b/plugins/libcalendaring/tests/resources/vtodo.ics
index 95261420..0d4534c4 100644
--- a/plugins/libcalendaring/tests/resources/vtodo.ics
+++ b/plugins/libcalendaring/tests/resources/vtodo.ics
@@ -28,6 +28,9 @@ STATUS:IN-PROCESS
 DTSTART;TZID=Europe/Zurich:20130921T000000
 DUE;VALUE=DATE:20130921
 SEQUENCE:2
+CATEGORIES:Tag1,Tag2
+CATEGORIES:Tag3
+CATEGORIES:Tag4
 X-MOZ-GENERATION:1
 BEGIN:VALARM
 ACTION:DISPLAY