diff --git a/.flake8 b/.flake8
index dffd549d..e5b0a13b 100644
--- a/.flake8
+++ b/.flake8
@@ -1,6 +1,6 @@
 [flake8]
 docstring-convention = google
-exclude = ./build, ./docs
+exclude = ./build, ./docs, ./__venv__
 extend-ignore =
     # D105 Missing docstring in magic method
     D105,
diff --git a/.gitignore b/.gitignore
index 3225aac8..63d2ad3b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 .vscode
 .python-version
 .pytest_cache/
+.mypy_cache/
 .idea/
 .coverage
 .spyproject/
@@ -15,3 +16,4 @@ docs/build/
 dist/
 env*
 *.egg-info/
+__venv__/
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 0afee19c..6e61c31a 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/psf/black
-    rev: 22.1.0
+    rev: 23.10.1
     hooks:
       - id: black-jupyter
 
@@ -10,7 +10,7 @@ repos:
       - id: flake8
 
   - repo: https://github.com/pycqa/isort
-    rev: 5.10.1
+    rev: 5.12.0
     hooks:
       - id: isort
         name: isort (python)
diff --git a/pulser-core/pulser/json/abstract_repr/serializer.py b/pulser-core/pulser/json/abstract_repr/serializer.py
index 07038dc0..0bc2e8ac 100644
--- a/pulser-core/pulser/json/abstract_repr/serializer.py
+++ b/pulser-core/pulser/json/abstract_repr/serializer.py
@@ -38,12 +38,14 @@
 class AbstractReprEncoder(json.JSONEncoder):
     """The custom encoder for abstract representation of Pulser objects."""
 
-    def default(self, o: Any) -> Union[dict[str, Any], list[Any]]:
+    def default(self, o: Any) -> dict[str, Any] | list | int:
         """Handles JSON encoding of objects not supported by default."""
         if hasattr(o, "_to_abstract_repr"):
             return cast(dict, o._to_abstract_repr())
         elif isinstance(o, np.ndarray):
             return cast(list, o.tolist())
+        elif isinstance(o, np.integer):
+            return int(o)
         elif isinstance(o, set):
             return list(o)
         else:
diff --git a/pulser-core/pulser/json/coders.py b/pulser-core/pulser/json/coders.py
index 989996f8..8dfa6a96 100644
--- a/pulser-core/pulser/json/coders.py
+++ b/pulser-core/pulser/json/coders.py
@@ -30,7 +30,7 @@
 class PulserEncoder(JSONEncoder):
     """The custom encoder for Pulser objects."""
 
-    def default(self, o: Any) -> dict[str, Any]:
+    def default(self, o: Any) -> dict[str, Any] | int:
         """Handles JSON encoding of objects not supported by default."""
         if hasattr(o, "_to_dict"):
             return cast(dict, o._to_dict())
@@ -38,6 +38,8 @@ def default(self, o: Any) -> dict[str, Any]:
             return obj_to_dict(o, _build=False, _name=o.__name__)
         elif isinstance(o, np.ndarray):
             return obj_to_dict(o, o.tolist(), _name="array")
+        elif isinstance(o, np.integer):
+            return int(o)
         elif isinstance(o, set):
             return obj_to_dict(o, list(o))
         else:
diff --git a/tests/test_abstract_repr.py b/tests/test_abstract_repr.py
index d85d85dd..9dab8064 100644
--- a/tests/test_abstract_repr.py
+++ b/tests/test_abstract_repr.py
@@ -939,6 +939,26 @@ def test_multi_qubit_target(self):
             "rhs": 2,
         }
 
+    def test_numpy_types(self):
+        assert (
+            json.loads(
+                json.dumps(np.array([12345])[0], cls=AbstractReprEncoder)
+            )
+            == 12345
+        )
+        assert (
+            json.loads(
+                json.dumps(np.array([np.pi])[0], cls=AbstractReprEncoder)
+            )
+            == np.pi
+        )
+        assert (
+            json.loads(
+                json.dumps(np.array(["abc"])[0], cls=AbstractReprEncoder)
+            )
+            == "abc"
+        )
+
 
 def _get_serialized_seq(
     operations: list[dict] = [],
diff --git a/tests/test_json.py b/tests/test_json.py
index 661021fb..566b274d 100644
--- a/tests/test_json.py
+++ b/tests/test_json.py
@@ -243,6 +243,12 @@ def test_type_error():
         Sequence._deserialize(json.loads(s))
 
 
+def test_numpy_types():
+    assert encode_decode(np.array([12])[0]) == 12
+    assert encode_decode(np.array([np.pi])[0]) == np.pi
+    assert encode_decode(np.array(["abc"])[0]) == "abc"
+
+
 def test_deprecated_device_args():
     seq = Sequence(Register.square(1), MockDevice)