diff --git a/lib/models/resources/ResourceBooking.class.php b/lib/models/resources/ResourceBooking.class.php
index dac56ad5d1dbb5db0a91bd4a7b2e2aa79cf2c1ab..5f3dd5e0f3272c5a54edc5bcbfd3b1e0afb0d6c9 100644
--- a/lib/models/resources/ResourceBooking.class.php
+++ b/lib/models/resources/ResourceBooking.class.php
@@ -466,8 +466,10 @@ class ResourceBooking extends SimpleORMap implements PrivacyObject, Studip\Calen
         }
 
         // update the booking user
-        $this->booking_user = User::findCurrent();
-    
+        if (!$this->isNew() || !$this->booking_user_id) {
+            $this->booking_user = User::findCurrent();
+        }
+
         //Check if the user has booking rights on the resource.
         //The user must have either permanent permissions or they have to
         //have booking rights by a temporary permission in this moment