diff --git a/sachet/server/files/views.py b/sachet/server/files/views.py
index 719af3e..9f5b2ac 100644
--- a/sachet/server/files/views.py
+++ b/sachet/server/files/views.py
@@ -2,7 +2,7 @@ import uuid
 import io
 from flask import Blueprint, request, jsonify, send_file, make_response
 from flask.views import MethodView
-from sachet.server.models import Share, Permissions, Upload, Chunk
+from sachet.server.models import Share, Permissions, Upload, Chunk, User
 from sachet.server.views_common import ModelAPI, ModelListAPI, auth_required
 from sachet.server import storage, db
 
@@ -28,6 +28,18 @@ class FilesMetadataAPI(ModelAPI):
                 ),
                 403,
             )
+        owner_name = request.get_json().get("owner_name")
+        if owner_name is not None:
+            if User.query.filter_by(username=owner_name).first() is None:
+                return (
+                    jsonify(
+                        {
+                            "status": "fail",
+                            "message": f"Invalid value for `owner_name`: {owner_name}",
+                        }
+                    ),
+                    400,
+                )
         if share.locked:
             return jsonify({"status": "fail", "message": "This share is locked."}), 423
         return super().patch(share)
@@ -45,6 +57,18 @@ class FilesMetadataAPI(ModelAPI):
                 ),
                 403,
             )
+        owner_name = request.get_json().get("owner_name")
+        if owner_name is not None:
+            if User.query.filter_by(username=owner_name).first() is None:
+                return (
+                    jsonify(
+                        {
+                            "status": "fail",
+                            "message": f"Invalid value for `owner_name`: {owner_name}",
+                        }
+                    ),
+                    400,
+                )
         if share.locked:
             return jsonify({"status": "fail", "message": "This share is locked."}), 423
         return super().put(share)
diff --git a/tests/test_files.py b/tests/test_files.py
index f7ff1ec..cf9a215 100644
--- a/tests/test_files.py
+++ b/tests/test_files.py
@@ -105,6 +105,42 @@ class TestSuite:
         assert resp.data == new_data
         assert "filename=new_bin.bin" in resp.headers["Content-Disposition"].split("; ")
 
+    def test_transfer(self, client, users, auth):
+        # create share
+        resp = client.post(
+            "/files", headers=auth("jeff"), json={"file_name": "content.bin"}
+        )
+        data = resp.get_json()
+        url = data.get("url")
+
+        # transfer ownership over to dave
+        resp = client.patch(url, headers=auth("jeff"), json={"owner_name": "dave"})
+        assert resp.status_code == 200
+
+        # ensure the transfer worked
+        resp = client.patch(
+            url, headers=auth("jeff"), json={"file_name": "jeff's file"}
+        )
+        assert resp.status_code == 403
+        resp = client.patch(
+            url, headers=auth("dave"), json={"file_name": "dave's file"}
+        )
+        assert resp.status_code == 200
+
+        # transfer ownership back to jeff
+        resp = client.patch(url, headers=auth("dave"), json={"owner_name": "jeff"})
+        assert resp.status_code == 200
+
+        # ensure the transfer worked
+        resp = client.patch(
+            url, headers=auth("dave"), json={"file_name": "dave's epic file"}
+        )
+        assert resp.status_code == 403
+        resp = client.patch(
+            url, headers=auth("jeff"), json={"file_name": "jeff's file"}
+        )
+        assert resp.status_code == 200
+
     def test_invalid(self, client, users, auth, rand, upload):
         """Test invalid requests."""
 
@@ -183,18 +219,22 @@ class TestSuite:
         )
         assert resp.status_code == 403
         resp = client.patch(
-            url,
-            headers=auth("dave"),
-            json=dict(file_name="epic_new_filename.bin")
+            url, headers=auth("dave"), json=dict(file_name="epic_new_filename.bin")
         )
         assert resp.status_code == 403
         resp = client.put(
             url,
             headers=auth("dave"),
-            json=dict(file_name="epic_new_filename.bin", owner_name="dave")
+            json=dict(file_name="epic_new_filename.bin", owner_name="dave"),
         )
         assert resp.status_code == 403
 
+        # test assigning a file to a non-existent user
+        resp = client.patch(
+            url, headers=auth("jeff"), json=dict(owner_name="non_existent_user")
+        )
+        assert resp.status_code == 400
+
         # test not allowing re-upload
         resp = upload(
             url + "/content",