diff --git a/tests/unittests/losses/test_config.py b/tests/unittests/losses/test_config.py
index cb00adbf3..49372baf1 100644
--- a/tests/unittests/losses/test_config.py
+++ b/tests/unittests/losses/test_config.py
@@ -1,35 +1,101 @@
 import pytest
+import torch
 from pydantic import ValidationError
 
-from clinicadl.losses import LossConfig
+from clinicadl.losses import ImplementedLoss
+from clinicadl.losses.config import (
+    BCEConfig,
+    BCEWithLogitsConfig,
+    CrossEntropyConfig,
+    HuberConfig,
+    KLDivConfig,
+    L1Config,
+    MSEConfig,
+    MultiMarginConfig,
+    NLLConfig,
+    SmoothL1Config,
+    create_loss_config,
+)
 
 
-def test_LossConfig():
-    config = LossConfig(
-        loss="SmoothL1Loss", margin=10.0, delta=2.0, reduction="none", weight=None
+@pytest.mark.parametrize(
+    "config,args",
+    [
+        (L1Config, {"reduction": "none"}),
+        (MSEConfig, {"reduction": "none"}),
+        (CrossEntropyConfig, {"reduction": "none"}),
+        (CrossEntropyConfig, {"weight": [1, -1, 2]}),
+        (CrossEntropyConfig, {"ignore_index": -1}),
+        (CrossEntropyConfig, {"label_smoothing": 1.1}),
+        (NLLConfig, {"reduction": "none"}),
+        (NLLConfig, {"weight": [1, -1, 2]}),
+        (NLLConfig, {"ignore_index": -1}),
+        (KLDivConfig, {"reduction": "none"}),
+        (BCEConfig, {"reduction": "none"}),
+        (BCEConfig, {"weight": [0, 1]}),
+        (BCEWithLogitsConfig, {"reduction": "none"}),
+        (BCEWithLogitsConfig, {"weight": [0, 1]}),
+        (BCEWithLogitsConfig, {"pos_weight": [[1, -1, 2]]}),
+        (BCEWithLogitsConfig, {"pos_weight": [["a", "b"]]}),
+        (HuberConfig, {"reduction": "none"}),
+        (HuberConfig, {"delta": 0.0}),
+        (SmoothL1Config, {"reduction": "none"}),
+        (SmoothL1Config, {"beta": -1.0}),
+        (MultiMarginConfig, {"reduction": "none"}),
+        (MultiMarginConfig, {"p": 3}),
+        (MultiMarginConfig, {"weight": [1, -1, 2]}),
+    ],
+)
+def test_validation_fail(config, args):
+    with pytest.raises((ValidationError, ValueError)):
+        config(**args)
+
+
+@pytest.mark.parametrize(
+    "config,args",
+    [
+        (L1Config, {"reduction": "mean"}),
+        (MSEConfig, {"reduction": "mean"}),
+        (
+            CrossEntropyConfig,
+            {
+                "reduction": "mean",
+                "weight": [1, 0, 2],
+                "ignore_index": 1,
+                "label_smoothing": 0.5,
+            },
+        ),
+        (NLLConfig, {"reduction": "mean", "weight": [1, 0, 2], "ignore_index": 1}),
+        (KLDivConfig, {"reduction": "mean", "log_target": True}),
+        (BCEConfig, {"reduction": "sum", "weight": None}),
+        (
+            BCEWithLogitsConfig,
+            {"reduction": "sum", "weight": None, "pos_weight": [[1, 0, 2]]},
+        ),
+        (HuberConfig, {"reduction": "sum", "delta": 0.1}),
+        (SmoothL1Config, {"reduction": "sum", "beta": 0.0}),
+        (
+            MultiMarginConfig,
+            {"reduction": "sum", "p": 1, "margin": -0.1, "weight": [1, 0, 2]},
+        ),
+    ],
+)
+def test_validation_pass(config, args):
+    c = config(**args)
+    for arg, value in args.items():
+        assert getattr(c, arg) == value
+
+
+def test_create_loss_config():
+    for loss in ImplementedLoss:
+        create_loss_config(loss)
+
+    config_class = create_loss_config("Multi Margin")
+    config = config_class(
+        margin=0.1,
+        reduction="sum",
     )
-    assert config.loss == "SmoothL1Loss"
-    assert config.margin == 10.0
-    assert config.delta == 2.0
-    assert config.reduction == "none"
+    assert isinstance(config, MultiMarginConfig)
     assert config.p == "DefaultFromLibrary"
-
-    with pytest.raises(ValueError):
-        LossConfig(loss="abc")
-    with pytest.raises(ValueError):
-        LossConfig(weight=[0.1, -0.1, 0.8])
-    with pytest.raises(ValueError):
-        LossConfig(p=3)
-    with pytest.raises(ValueError):
-        LossConfig(reduction="abc")
-    with pytest.raises(ValidationError):
-        LossConfig(label_smoothing=1.1)
-    with pytest.raises(ValidationError):
-        LossConfig(ignore_index=-1)
-    with pytest.raises(ValidationError):
-        LossConfig(loss="BCEWithLogitsLoss", weight=[1, 2, 3])
-    with pytest.raises(ValidationError):
-        LossConfig(loss="BCELoss", weight=[1, 2, 3])
-
-    LossConfig(loss="BCELoss")
-    LossConfig(loss="BCEWithLogitsLoss", weight=None)
+    assert config.margin == 0.1
+    assert config.reduction == "sum"
diff --git a/tests/unittests/losses/test_factory.py b/tests/unittests/losses/test_factory.py
index 5ac786deb..5396bac3d 100644
--- a/tests/unittests/losses/test_factory.py
+++ b/tests/unittests/losses/test_factory.py
@@ -1,15 +1,15 @@
 from torch import Tensor
 from torch.nn import BCEWithLogitsLoss, MultiMarginLoss
 
-from clinicadl.losses import ImplementedLoss, LossConfig, get_loss_function
+from clinicadl.losses import ImplementedLoss, create_loss_config, get_loss_function
 
 
 def test_get_loss_function():
-    for loss in [e.value for e in ImplementedLoss]:
-        config = LossConfig(loss=loss)
-        get_loss_function(config)
+    for loss in ImplementedLoss:
+        config = create_loss_config(loss=loss)()
+        _ = get_loss_function(config)
 
-    config = LossConfig(loss="MultiMarginLoss", reduction="sum", weight=[1, 2, 3], p=2)
+    config = create_loss_config("Multi Margin")(reduction="sum", weight=[1, 2, 3], p=2)
     loss, updated_config = get_loss_function(config)
     assert isinstance(loss, MultiMarginLoss)
     assert loss.reduction == "sum"
@@ -23,7 +23,7 @@ def test_get_loss_function():
     assert updated_config.margin == 1.0
     assert updated_config.weight == [1, 2, 3]
 
-    config = LossConfig(loss="BCEWithLogitsLoss", pos_weight=[1, 2, 3])
+    config = create_loss_config("BCE With Logits")(pos_weight=[1, 2, 3])
     loss, updated_config = get_loss_function(config)
     assert isinstance(loss, BCEWithLogitsLoss)
     assert (loss.pos_weight == Tensor([1, 2, 3])).all()