diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8ab7d800f5..27f0af4128 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,7 @@ into pre-release sections below.
     * Do not process task sources in task/task-group CRUD operations (\#1861).
     * Do not process task owners in task/task-group CRUD operations (\#1861).
     * Expand use and validators for `TaskGroupCreateV2` schema (\#1861).
+    * Forbid extras in `TaskCollectPipV2` (\#1891).
 * Database:
     * Add `taskgroupv2_id` foreign key to `CollectionStateV2` (\#1867).
     * Make `TaskV2.source` nullable and drop its uniqueness constraint (\#1861).
diff --git a/fractal_server/app/schemas/v2/task_collection.py b/fractal_server/app/schemas/v2/task_collection.py
index 08fb9935c5..17bfa52dd3 100644
--- a/fractal_server/app/schemas/v2/task_collection.py
+++ b/fractal_server/app/schemas/v2/task_collection.py
@@ -6,6 +6,7 @@
 from typing import Optional
 
 from pydantic import BaseModel
+from pydantic import Extra
 from pydantic import root_validator
 from pydantic import validator
 
@@ -24,7 +25,7 @@ class CollectionStatusV2(str, Enum):
     OK = "OK"
 
 
-class TaskCollectPipV2(BaseModel):
+class TaskCollectPipV2(BaseModel, extra=Extra.forbid):
     """
     TaskCollectPipV2 class
 
diff --git a/tests/v2/03_api/test_api_task_collection.py b/tests/v2/03_api/test_api_task_collection.py
index bb528963ce..631368251e 100644
--- a/tests/v2/03_api/test_api_task_collection.py
+++ b/tests/v2/03_api/test_api_task_collection.py
@@ -400,7 +400,6 @@ async def test_task_collection_custom(
             source="source1",
             package_root=None,
             package_name=package_name,
-            version=None,
         )
 
         # Fail because no package is installed in sys.executable
@@ -442,7 +441,6 @@ async def test_task_collection_custom(
             source="source3",
             package_root=package_root,
             package_name=None,
-            version=None,
         )
         res = await client.post(
             f"{PREFIX}/collect/custom/", json=payload_root.dict()
diff --git a/tests/v2/03_api/test_api_task_collection_ssh.py b/tests/v2/03_api/test_api_task_collection_ssh.py
index ac88b5918b..8912f6d6c0 100644
--- a/tests/v2/03_api/test_api_task_collection_ssh.py
+++ b/tests/v2/03_api/test_api_task_collection_ssh.py
@@ -270,9 +270,12 @@ async def test_task_collection_ssh_from_wheel(
             f"{PREFIX}/collect/pip/",
             json=dict(
                 package=remote_wheel_path,
-                version="1.2.3",
+                package_version="1.2.3",
                 python_version=current_py_version,
             ),
         )
         assert res.status_code == 422
-        debug(res.json())
+        error_msg = (
+            "Cannot provide package version when package " "is a wheel file."
+        )
+        assert error_msg in str(res.json()["detail"])