diff --git a/src/classes/statistic_classes.py b/src/classes/statistic_classes.py
index 11d3418..79c01cb 100644
--- a/src/classes/statistic_classes.py
+++ b/src/classes/statistic_classes.py
@@ -16,6 +16,13 @@ class GameOrderStatistic(StatisticBase):
         boardgame_classes.OwnedBoardGame, boardgame_classes.OwnedBoardGameExpansion,
         boardgame_classes.WishlistBoardGame, boardgame_classes.WishlistBoardGameExpansion]]
 
+    model_config = {
+        'validate_assignment':True
+    }
 
 class TimeLineStatistic(StatisticBase):
-    result: Dict[date, int]
\ No newline at end of file
+    result: Dict[date, int]
+
+    model_config = {
+        'validate_assignment':True
+    }
\ No newline at end of file
diff --git a/tests/test_main.py b/tests/test_main.py
index 1d288e0..c1a7402 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,7 +1,7 @@
 import validators
 from fastapi.testclient import TestClient
 from datetime import date
-from typing import Union
+from typing import Union, Dict
 
 from src.main import app
 
@@ -25,6 +25,9 @@ def default_boardgame_test(to_test_boardgame: boardgame_classes.BoardGame):
     assert type(to_test_boardgame.type) == boardgame_classes.BoardgameType
 
 
+def default_statistic_test(to_test_statistic: statistic_classes.StatisticBase):
+    assert type(to_test_statistic.name) == str, to_test_statistic
+
 
 def test_read_main():
     response = client.get("/")
@@ -35,7 +38,7 @@ def test_retrieve_boardgame():
     response = client.get("/boardgame?id=373167")
     assert response.status_code == 200
 
-    returned_boardgame = boardgame_classes.BoardGame(**response.json())
+    returned_boardgame = boardgame_classes.BoardGame.model_validate(response.json())
 
     default_boardgame_test(returned_boardgame)
 
@@ -43,7 +46,7 @@ def test_retrieve_owned():
     response = client.get("/owned")
     assert response.status_code == 200
 
-    returned_boardgame = boardgame_classes.OwnedBoardGame(**response.json()[0])
+    returned_boardgame = boardgame_classes.OwnedBoardGame.model_validate(response.json()[0])
 
     default_boardgame_test(returned_boardgame)
     assert type(returned_boardgame.price_paid) == float
@@ -55,7 +58,7 @@ def test_retrieve_wishlist():
     response = client.get("/wishlist")
     assert response.status_code == 200
 
-    returned_boardgame = boardgame_classes.WishlistBoardGame(**response.json()[0])
+    returned_boardgame = boardgame_classes.WishlistBoardGame.model_validate(response.json()[0])
 
     default_boardgame_test(returned_boardgame)
     assert type(returned_boardgame.wishlist_priority) == int
@@ -91,7 +94,39 @@ def test_retrieve_basic_statistic():
     response = client.get("/statistics/amount_of_games")
     assert response.status_code == 200
 
-    returned_statistic = statistic_classes.NumberStatistic(**response.json())
+    returned_statistic = statistic_classes.NumberStatistic.model_validate(response.json())
 
-    assert type(returned_statistic.name) == str
-    assert type(returned_statistic.result) == float
\ No newline at end of file
+    default_statistic_test(returned_statistic)
+    assert type(returned_statistic.result) == float
+
+
+def test_retrieve_timeline_statistic():
+    response = client.get("/statistics/amount_of_games_over_time")
+    assert response.status_code == 200
+
+    returned_statistic = statistic_classes.TimeLineStatistic.model_validate(response.json())
+
+    default_statistic_test(returned_statistic)
+    assert type(returned_statistic.result) == dict
+
+    response = client.get("/statistics/games_played_per_year")
+    assert response.status_code == 200
+
+    returned_statistic = statistic_classes.TimeLineStatistic.model_validate(response.json())
+
+    default_statistic_test(returned_statistic)
+    assert type(returned_statistic.result) == dict
+
+
+def test_retrieve_game_order_statistic():
+    response = client.get("/statistics/most_expensive_games")
+    assert response.status_code == 200
+
+    returned_statistic = statistic_classes.GameOrderStatistic.model_validate(response.json())
+
+    default_statistic_test(returned_statistic)
+    assert type(returned_statistic.result) == list
+    assert type(returned_statistic.result[0]) in [
+        boardgame_classes.BoardGame, boardgame_classes.BoardGameExpansion,
+        boardgame_classes.OwnedBoardGame, boardgame_classes.OwnedBoardGameExpansion,
+        boardgame_classes.WishlistBoardGame, boardgame_classes.WishlistBoardGameExpansion]
\ No newline at end of file