diff --git a/application/Api/v1/PreorderApicontroller.php b/application/Api/v1/PreorderApicontroller.php
index 72eb12a7f..bf2e49999 100644
--- a/application/Api/v1/PreorderApicontroller.php
+++ b/application/Api/v1/PreorderApicontroller.php
@@ -311,6 +311,13 @@ class PreorderApicontroller extends mfBaseApicontroller {
         $unit_search[$key] = trim($this->post['address']->$key);
       }
     }
+    
+    
+    // ignore unit_string if the specific fields were provided
+    if($unit_search['block'] || $unit_search['stiege'] || $unit_search['stock'] || $unit_search['tuer']) {
+      unset($unit_search['unit_string']);
+    }
+    
     if($zusatz) {
       $unit_search['zusatz'] = $zusatz;
     }
@@ -592,6 +599,7 @@ class PreorderApicontroller extends mfBaseApicontroller {
           }
         }
       }
+
       // get units excluding unavailable units
       $where = "hausnummer_id=".$address->hausnummer_id;
       $where .= " AND ( block = '' OR block IS NULL)";