diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index 1034a745..abecc9dd 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -11,13 +11,16 @@ on:
 jobs:
   python-tests:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.8, 3.12]
     steps:
       - name: "Checkout branch"
         uses: actions/checkout@v4
       - name: "Set up Python on Ubuntu"
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v2
         with:
-          python-version: 3.12
+          python-version: ${{ matrix.python-version }}
       - name: "Python codestyle"
         run: |
           pip install ".[dev]"
diff --git a/src/ipyaladin/__init__.py b/src/ipyaladin/__init__.py
index b968c5dc..67a9499e 100644
--- a/src/ipyaladin/__init__.py
+++ b/src/ipyaladin/__init__.py
@@ -1,5 +1,6 @@
 import importlib.metadata
 import pathlib
+import typing
 from typing import ClassVar, Union, Final, Optional
 import warnings
 
@@ -7,13 +8,12 @@
 from astropy.table.table import QTable
 from astropy.table import Table
 from astropy.coordinates import SkyCoord, Angle
+import traitlets
 from traitlets import (
     Float,
     Int,
     Unicode,
     Bool,
-    List,
-    Dict,
     Any,
     default,
 )
@@ -86,21 +86,21 @@ class Aladin(anywidget.AnyWidget):
     show_coo_grid_control = Bool(True).tag(sync=True, init_option=True)
     grid_color = Unicode("rgb(178, 50, 178)").tag(sync=True, init_option=True)
     grid_opacity = Float(0.5).tag(sync=True, init_option=True)
-    grid_options = Dict().tag(sync=True, init_option=True)
+    grid_options = traitlets.Dict().tag(sync=True, init_option=True)
 
     # content of the last click
-    clicked_object = Dict().tag(sync=True)
+    clicked_object = traitlets.Dict().tag(sync=True)
     # listener callback is on the python side and contains functions to link to events
-    listener_callback: ClassVar[dict[str, callable]] = {}
+    listener_callback: ClassVar[typing.Dict[str, callable]] = {}
 
     # overlay survey
     overlay_survey = Unicode("").tag(sync=True, init_option=True)
     overlay_survey_opacity = Float(0.0).tag(sync=True, init_option=True)
 
-    init_options = List(trait=Any()).tag(sync=True)
+    init_options = traitlets.List(trait=Any()).tag(sync=True)
 
     @default("init_options")
-    def _init_options(self) -> list[str]:
+    def _init_options(self) -> typing.List[str]:
         return list(self.traits(init_option=True))
 
     def __init__(self, *args: any, **kwargs: any) -> None:
diff --git a/src/ipyaladin/coordinate_parser.py b/src/ipyaladin/coordinate_parser.py
index 5dd3dc2a..a23e1ce3 100644
--- a/src/ipyaladin/coordinate_parser.py
+++ b/src/ipyaladin/coordinate_parser.py
@@ -1,3 +1,5 @@
+from typing import Tuple
+
 from astropy.coordinates import SkyCoord, Angle
 import re
 
@@ -18,7 +20,7 @@ def parse_coordinate_string(string: str) -> SkyCoord:
     """
     if not _is_coordinate_string(string):
         return SkyCoord.from_name(string)
-    coordinates: tuple[str, str] = _split_coordinate_string(string)
+    coordinates: Tuple[str, str] = _split_coordinate_string(string)
     # Parse ra and dec to astropy Angle objects
     dec: Angle = Angle(coordinates[1], unit="deg")
     if _is_hour_angle_string(coordinates[0]):
@@ -51,7 +53,7 @@ def _is_coordinate_string(string: str) -> bool:
     return bool(re.match(regex, string))
 
 
-def _split_coordinate_string(coo: str) -> tuple[str, str]:
+def _split_coordinate_string(coo: str) -> Tuple[str, str]:
     """Split a string containing coordinates in two parts.
 
     Parameters
diff --git a/src/test/test_coordinate_parser.py b/src/test/test_coordinate_parser.py
index 7f2c317e..b399bc4a 100644
--- a/src/test/test_coordinate_parser.py
+++ b/src/test/test_coordinate_parser.py
@@ -1,3 +1,4 @@
+from typing import Tuple
 from ipyaladin.coordinate_parser import (
     parse_coordinate_string,
     _split_coordinate_string,
@@ -67,7 +68,7 @@ def test_is_coordinate_string(inp: str, expected: bool) -> None:
 
 
 @pytest.mark.parametrize(("inp", "expected"), test_split_coordinate_string_values)
-def test_split_coordinate_string(inp: str, expected: tuple[str, str]) -> None:
+def test_split_coordinate_string(inp: str, expected: Tuple[str, str]) -> None:
     """Test the function _split_coordinate_string.
 
     Parameters