diff --git a/src/caosdb/high_level_api.py b/src/caosdb/high_level_api.py
index 87ff7c5fec6ac670b112e019fc04232f431745da..427a095a4bafc0c372b0169298f2980dbd902c49 100644
--- a/src/caosdb/high_level_api.py
+++ b/src/caosdb/high_level_api.py
@@ -60,23 +60,23 @@ def standard_type_for_high_level_type(high_level_record: "CaosDBPythonEntity",
     class in the standard CaosDB API or - if return_string is True - return
     the role as a string.
     """
-    if isinstance(high_level_record, CaosDBPythonRecord):
+    if type(high_level_record) == CaosDBPythonRecord:
         if not return_string:
             return db.Record
         return "Record"
-    elif isinstance(high_level_record, CaosDBPythonFile):
+    elif type(high_level_record) == CaosDBPythonFile:
         if not return_string:
             return db.File
         return "File"
-    elif isinstance(high_level_record, CaosDBPythonProperty):
+    elif type(high_level_record) == CaosDBPythonProperty:
         if not return_string:
             return db.Property
         return "Property"
-    elif isinstance(high_level_record, CaosDBPythonRecordType):
+    elif type(high_level_record) == CaosDBPythonRecordType:
         if not return_string:
             return db.RecordType
         return "RecordType"
-    elif isinstance(high_level_record, CaosDBPythonEntity):
+    elif type(high_level_record) == CaosDBPythonEntity:
         if not return_string:
             return db.Entity
         return "Entity"
@@ -101,15 +101,15 @@ def high_level_type_for_standard_type(standard_record: db.Entity):
     if not isinstance(standard_record, db.Entity):
         raise ValueError()
     role = standard_record.role
-    if role == "Record" or isinstance(standard_record, db.Record):
+    if role == "Record" or type(standard_record) == db.Record:
         return CaosDBPythonRecord
-    elif role == "File" or isinstance(standard_record, db.File):
+    elif role == "File" or type(standard_record) == db.File:
         return CaosDBPythonFile
-    elif role == "Property" or isinstance(standard_record, db.Property):
+    elif role == "Property" or type(standard_record) == db.Property:
         return CaosDBPythonProperty
-    elif role == "RecordType" or isinstance(standard_record, db.RecordType):
+    elif role == "RecordType" or type(standard_record) == db.RecordType:
         return CaosDBPythonRecordType
-    elif role == "Entity" or isinstance(standard_record, db.Entity):
+    elif role == "Entity" or type(standard_record) == db.Entity:
         return CaosDBPythonEntity
     raise RuntimeError("Incompatible type.")
 
@@ -213,14 +213,14 @@ class CaosDBPythonEntity(object):
         """
         Getter for the file.
         """
-        if not isinstance(self, CaosDBPythonFile):
+        if type(self) != CaosDBPythonFile:
             raise RuntimeError("Please don't use the file attribute for entities"
                                " that are no files.")
         return self._file
 
     @file.setter
     def file(self, val: str):
-        if val is not None and not isinstance(self, CaosDBPythonFile):
+        if val is not None and type(self) != CaosDBPythonFile:
             raise RuntimeError("Please don't use the file attribute for entities"
                                " that are no files.")
         self._file = val
@@ -230,14 +230,14 @@ class CaosDBPythonEntity(object):
         """
         Getter for the path.
         """
-        if not isinstance(self, CaosDBPythonFile):
+        if type(self) != CaosDBPythonFile:
             raise RuntimeError("Please don't use the path attribute for entities"
                                " that are no files.")
         return self._path
 
     @path.setter
     def path(self, val: str):
-        if val is not None and not isinstance(self, CaosDBPythonFile):
+        if val is not None and type(self) != CaosDBPythonFile:
             raise RuntimeError("Please don't use the path attribute for entities"
                                " that are no files.")
         self._path = val
@@ -646,7 +646,7 @@ class CaosDBPythonEntity(object):
             if baseprop in serialization:
                 entity.__setattr__(baseprop, serialization[baseprop])
 
-        if isinstance(entity, CaosDBPythonFile):
+        if type(entity) == CaosDBPythonFile:
             entity.file = serialization["file"]
             entity.path = serialization["path"]
 
@@ -717,7 +717,7 @@ class CaosDBPythonEntity(object):
             if val is not None:
                 fulldict[baseprop] = val
 
-        if isinstance(self, CaosDBPythonFile):
+        if type(self) == CaosDBPythonFile:
             fulldict["file"] = self.file
             fulldict["path"] = self.path