diff --git a/src/caosdb/utils/plantuml.py b/src/caosdb/utils/plantuml.py
index 2245d0ef8f0fe19d155a5196de8794f8f983a775..be34b2604f3682bb71b48bbd73e00fe854b3af51 100644
--- a/src/caosdb/utils/plantuml.py
+++ b/src/caosdb/utils/plantuml.py
@@ -223,6 +223,7 @@ package \"The property P references an instance of D\" <<Rectangle>> {
 
     return result
 
+
 def retrieve_substructure(start_record_types, depth, result_id_set=None, result_container=None, cleanup=True):
     """Recursively retrieves CaosDB record types and properties, starting
     from given initial types up to a specific depth.
@@ -262,11 +263,11 @@ def retrieve_substructure(start_record_types, depth, result_id_set=None, result_
             if is_reference(prop.datatype) and prop.datatype != db.FILE and depth > 0:
                 rt = db.RecordType(name=get_referenced_recordtype(prop.datatype)).retrieve()
                 retrieve_substructure([rt], depth-1, result_id_set, result_container, False)
-            else:
-                if prop.id not in result_id_set:
-                    result_container.append(prop)
+
+            if prop.id not in result_id_set:
+                result_container.append(prop)
                 result_id_set.add(prop.id)
-                
+
         for parent in entity.parents:
             rt = db.RecordType(id=parent.id).retrieve()
             if parent.id not in result_id_set:
@@ -278,14 +279,14 @@ def retrieve_substructure(start_record_types, depth, result_id_set=None, result_
     if cleanup:
         return result_container
     return None
-        
-    
+
+
 def to_graphics(recordtypes, filename):
     """Calls recordtypes_to_plantuml_string(), saves result to file and
     creates an svg image
 
     plantuml needs to be installed.
-    
+
     Parameters
     ----------
     recordtypes : Iterable[db.Entity]
@@ -296,7 +297,6 @@ def to_graphics(recordtypes, filename):
     """
     pu = recordtypes_to_plantuml_string(recordtypes)
 
-
     pu_filename = filename+".pu"
     with open(pu_filename, "w") as pu_file:
         pu_file.write(pu)