diff --git a/tests/v2/01_schemas/test_schemas_workflow.py b/tests/v2/01_schemas/test_schemas_workflow.py
index c6f61674f2..784922d199 100644
--- a/tests/v2/01_schemas/test_schemas_workflow.py
+++ b/tests/v2/01_schemas/test_schemas_workflow.py
@@ -37,12 +37,10 @@ async def test_schemas_workflow_v2():
     with pytest.raises(ValidationError):
         WorkflowUpdateV2(name=None)
 
-    workflow_update = WorkflowUpdateV2(name="new name")
-
-    for key, value in workflow_update.dict(exclude_unset=True).items():
-        setattr(workflow, key, value)
+    with pytest.raises(ValidationError):
+        WorkflowUpdateV2(name="foo", reordered_workflowtask_ids=[1, 2, -3])
 
-    assert workflow.name == "new name"
+    WorkflowUpdateV2(name="new name", reordered_workflowtask_ids=[1, 2, 3])
 
 
 async def test_schemas_workflow_task_v2():
diff --git a/tests/v2/01_schemas/test_task_collection.py b/tests/v2/01_schemas/test_task_collection.py
index dc366b7c6f..15760f08a8 100644
--- a/tests/v2/01_schemas/test_task_collection.py
+++ b/tests/v2/01_schemas/test_task_collection.py
@@ -18,6 +18,11 @@ def test_TaskCollectPipV2():
     assert collection.package == "package"
     assert collection.package_version == "1.2.3"
 
+    with pytest.raises(
+        ValidationError, match="Local-package path must be absolute"
+    ):
+        TaskCollectPipV2(package="not/absolute.whl")
+
 
 async def test_TaskCollectCustomV2(testdata_path):
 
diff --git a/tests/v2/01_schemas/test_unit_schemas_v2.py b/tests/v2/01_schemas/test_unit_schemas_v2.py
index 8cca775a73..5e773de71c 100644
--- a/tests/v2/01_schemas/test_unit_schemas_v2.py
+++ b/tests/v2/01_schemas/test_unit_schemas_v2.py
@@ -6,8 +6,11 @@
 from fractal_server.app.schemas.v2 import ProjectCreateV2
 from fractal_server.app.schemas.v2 import TaskCollectPipV2
 from fractal_server.app.schemas.v2 import TaskCreateV2
+from fractal_server.app.schemas.v2 import TaskUpdateV2
 from fractal_server.app.schemas.v2 import WorkflowCreateV2
 from fractal_server.app.schemas.v2 import WorkflowTaskCreateV2
+from fractal_server.app.schemas.v2 import WorkflowTaskDumpV2
+from fractal_server.images import Filters
 
 
 def test_extra_on_create_models():
@@ -77,6 +80,11 @@ def test_dictionary_keys_validation():
     with pytest.raises(ValidationError):
         TaskCreateV2(**args, input_types={"a": True, "  a   ": False})
 
+    with pytest.raises(
+        ValidationError, match="Task must have at least one valid command"
+    ):
+        TaskCreateV2(name="name", source="source")
+
 
 def test_task_collect_pip():
 
@@ -93,3 +101,47 @@ def test_task_collect_pip():
         TaskCollectPipV2(package="/tmp/x.whl", package_version="1")
     msg = "Cannot provide package version when package is a wheel file"
     assert msg in str(e.value)
+
+
+def test_task_update():
+    t = TaskUpdateV2()
+    assert t.input_types is None
+    assert t.output_types is None
+    with pytest.raises(ValidationError):
+        TaskUpdateV2(input_types=None)
+    with pytest.raises(ValidationError):
+        TaskUpdateV2(output_types=None)
+
+
+def test_job_create():
+    JobCreateV2()
+    JobCreateV2(last_task_index=None)
+    JobCreateV2(last_task_index=1)
+    with pytest.raises(ValidationError, match="cannot be negative"):
+        JobCreateV2(last_task_index=-1)
+
+
+def test_workflow_task_dump():
+    WorkflowTaskDumpV2(
+        id=1,
+        workflow_id=1,
+        is_legacy_task=False,
+        input_filters=Filters(),
+        task_id=1,
+    )
+    with pytest.raises(ValidationError, match="both"):
+        WorkflowTaskDumpV2(
+            id=1,
+            workflow_id=1,
+            is_legacy_task=False,
+            input_filters=Filters(),
+            task_id=1,
+            task_legacy_id=1,
+        )
+    with pytest.raises(ValidationError, match="none"):
+        WorkflowTaskDumpV2(
+            id=1,
+            workflow_id=1,
+            is_legacy_task=False,
+            input_filters=Filters(),
+        )