diff --git a/tests/data_service/test_state_manager.py b/tests/data_service/test_state_manager.py
index f5674df..ba593c0 100644
--- a/tests/data_service/test_state_manager.py
+++ b/tests/data_service/test_state_manager.py
@@ -9,8 +9,13 @@ import pydase.units as u
 from pydase.data_service.state_manager import StateManager
 
 
+class SubService(pydase.DataService):
+    name = "SubService"
+
+
 class Service(pydase.DataService):
     def __init__(self, **kwargs: Any) -> None:
+        self.subservice = SubService()
         self.some_unit: u.Quantity = 1.2 * u.units.A
         self.some_float = 1.0
         self._name = "Service"
@@ -21,37 +26,18 @@ class Service(pydase.DataService):
         return self._name
 
 
-CURRENT_STATE = {
-    "name": {
-        "type": "str",
-        "value": "Service",
-        "readonly": True,
-        "doc": None,
-    },
-    "some_float": {
-        "type": "float",
-        "value": 1.0,
-        "readonly": False,
-        "doc": None,
-    },
-    "some_unit": {
-        "type": "Quantity",
-        "value": {"magnitude": 1.2, "unit": "A"},
-        "readonly": False,
-        "doc": None,
-    },
-}
+CURRENT_STATE = Service().serialize()
 
 LOAD_STATE = {
     "name": {
         "type": "str",
-        "value": "Service",
+        "value": "Another name",
         "readonly": True,
         "doc": None,
     },
     "some_float": {
         "type": "int",
-        "value": 1,
+        "value": 10,
         "readonly": False,
         "doc": None,
     },
@@ -61,6 +47,25 @@ LOAD_STATE = {
         "readonly": False,
         "doc": None,
     },
+    "subservice": {
+        "type": "DataService",
+        "value": {
+            "name": {
+                "type": "str",
+                "value": "SubService",
+                "readonly": False,
+                "doc": None,
+            }
+        },
+        "readonly": False,
+        "doc": None,
+    },
+    "removed_attr": {
+        "type": "str",
+        "value": "removed",
+        "readonly": False,
+        "doc": None,
+    },
 }
 
 
@@ -76,7 +81,7 @@ def test_save_state(tmp_path: Path):
     assert file.read_text() == json.dumps(CURRENT_STATE, indent=4)
 
 
-def test_load_state(tmp_path: Path):
+def test_load_state(tmp_path: Path, caplog: LogCaptureFixture):
     # Create a StateManager instance with a temporary file
     file = tmp_path / "test_state.json"
 
@@ -87,7 +92,26 @@ def test_load_state(tmp_path: Path):
     service = Service()
     manager = StateManager(service=service, filename=str(file))
     manager.load_state()
-    assert service.some_unit == u.Quantity(12, "A")
+
+    assert service.some_unit == u.Quantity(12, "A")  # has changed
+    assert service.name == "Service"  # has not changed as readonly
+    assert service.some_float == 1.0  # has not changed due to different type
+    assert service.some_float == 1.0  # has not changed due to different type
+    assert service.subservice.name == "SubService"  # didn't change
+
+    assert "Service.some_unit changed to 12.0 A!" in caplog.text
+    assert (
+        "Attribute 'name' is read-only. Ignoring value from JSON file..." in caplog.text
+    )
+    assert (
+        "Attribute type of 'some_float' changed from 'int' to 'float'. "
+        "Ignoring value from JSON file..."
+    ) in caplog.text
+    assert (
+        "Attribute type of 'removed_attr' changed from 'str' to None. "
+        "Ignoring value from JSON file..." in caplog.text
+    )
+    assert "Value of attribute 'subservice.name' has not changed..." in caplog.text
 
 
 def test_filename_warning(tmp_path: Path, caplog: LogCaptureFixture):