diff --git a/parcels/fieldset.py b/parcels/fieldset.py
index 3f02cad20..94c1beae1 100644
--- a/parcels/fieldset.py
+++ b/parcels/fieldset.py
@@ -1309,7 +1309,7 @@ def from_modulefile(cls, filename, modulename="create_fieldset", **kwargs):
         """
         # check if filename exists
         if not os.path.exists(filename):
-            raise IOError(f"FieldSet module file {filename} does not exist")
+            raise OSError(f"FieldSet module file {filename} does not exist")
 
         # Importing the source file directly (following https://docs.python.org/3/library/importlib.html#importing-a-source-file-directly)
         spec = importlib.util.spec_from_file_location(modulename, filename)
@@ -1318,10 +1318,10 @@ def from_modulefile(cls, filename, modulename="create_fieldset", **kwargs):
         spec.loader.exec_module(fieldset_module)
 
         if not hasattr(fieldset_module, modulename):
-            raise IOError(f"{filename} does not contain a {modulename} function")
+            raise OSError(f"{filename} does not contain a {modulename} function")
         fieldset = getattr(fieldset_module, modulename)(**kwargs)
         if not isinstance(fieldset, FieldSet):
-            raise IOError(f"Module {filename}.{modulename} does not return a FieldSet object")
+            raise OSError(f"Module {filename}.{modulename} does not return a FieldSet object")
         return fieldset
 
     def get_fields(self):
diff --git a/parcels/particleset.py b/parcels/particleset.py
index c4007cf20..c1b958cc1 100644
--- a/parcels/particleset.py
+++ b/parcels/particleset.py
@@ -155,7 +155,7 @@ def ArrayClass_init(self, *args, **kwargs):
         lon = np.empty(shape=0) if lon is None else convert_to_flat_array(lon)
         lat = np.empty(shape=0) if lat is None else convert_to_flat_array(lat)
 
-        if isinstance(pid_orig, (type(None), type(False))):
+        if isinstance(pid_orig, (type(None), bool)):
             pid_orig = np.arange(lon.size)
 
         if depth is None:
diff --git a/parcels/tools/exampledata_utils.py b/parcels/tools/exampledata_utils.py
index 07e59e3a8..a57b2b4c3 100644
--- a/parcels/tools/exampledata_utils.py
+++ b/parcels/tools/exampledata_utils.py
@@ -1,7 +1,6 @@
 import os
 from datetime import datetime, timedelta
 from pathlib import Path
-from typing import List
 from urllib.request import urlretrieve
 
 import platformdirs
@@ -96,7 +95,7 @@ def get_data_home(data_home=None):
     return data_home
 
 
-def list_example_datasets() -> List[str]:
+def list_example_datasets() -> list[str]:
     """List the available example datasets.
 
     Use :func:`download_example_dataset` to download one of the datasets.
diff --git a/pyproject.toml b/pyproject.toml
index d42401fbe..64f1927a9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -66,7 +66,7 @@ select = [
     "F",  # pyflakes
     "I",  # isort
     "B",  # Bugbear
-    # "UP", # pyupgrade
+    "UP", # pyupgrade
     "LOG", # logging
     "ICN", # import conventions
     "G", # logging-format