diff --git a/includes/model/Shifts_model.php b/includes/model/Shifts_model.php
index 37c772bf..a0cdbe5d 100644
--- a/includes/model/Shifts_model.php
+++ b/includes/model/Shifts_model.php
@@ -43,11 +43,23 @@ function Shift_signup_allowed($shift, $angeltype, $user_angeltype = null, $user_
       $signed_up = true;
       break;
     }
+  
+  $needed_angeltypes = NeededAngelTypes_by_shift($shift['SID']);
+  if ($needed_angeltypes === false)
+    engelsystem_error('Unable to load needed angel types.');
     
     // is the shift still running or alternatively is the user shift admin?
   $user_may_join_shift = true;
   
-  // you cannot join if user alread joined a parallel or this shift
+  // you canot join if shift is full
+  foreach ($needed_angeltypes as $needed_angeltype)
+    if ($needed_angeltype['angel_type_id'] == $angeltype['id']) {
+      if ($needed_angeltype['taken'] >= $needed_angeltype['count'])
+        $user_may_join_shift = false;
+      break;
+    }
+    
+    // you cannot join if user alread joined a parallel or this shift
   $user_may_join_shift &= ! $collides;
   
   // you cannot join if you already singed up for this shift
diff --git a/includes/pages/user_shifts.php b/includes/pages/user_shifts.php
index f4e2de67..81bc5f54 100644
--- a/includes/pages/user_shifts.php
+++ b/includes/pages/user_shifts.php
@@ -253,6 +253,18 @@ function user_shifts() {
       redirect(shift_link($shift));
     }
     
+    $needed_angeltypes = NeededAngelTypes_by_shift($shift['SID']);
+    if ($needed_angeltypes === false)
+      engelsystem_error('Unable to load needed angel types.');
+      
+      // you canot join if shift is full
+    foreach ($needed_angeltypes as $needed_angeltype)
+      if ($needed_angeltype['angel_type_id'] == $type_id)
+        if ($needed_angeltype['taken'] >= $needed_angeltype['count']) {
+          error(_("The shift is already full."));
+          redirect(shift_link($shift));
+        }
+    
     if (in_array('user_shifts_admin', $privileges))
       $type = sql_select("SELECT * FROM `AngelTypes` WHERE `id`=" . sql_escape($type_id) . " LIMIT 1");
     else