diff --git a/datasette/app.py b/datasette/app.py
index ca2efa91..c684eabc 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -908,6 +908,7 @@ class DatasetteRouter(AsgiRouter):
         ):
             scope_modifications["scheme"] = "https"
         # Handle authentication
+        default_actor = scope.get("actor") or None
         actor = None
         for actor in pm.hook.actor_from_request(
             datasette=self.ds, request=Request(scope, receive)
@@ -918,7 +919,7 @@ class DatasetteRouter(AsgiRouter):
                 actor = await actor
             if actor:
                 break
-        scope_modifications["actor"] = actor
+        scope_modifications["actor"] = actor or default_actor
         return await super().route_path(
             dict(scope, **scope_modifications), receive, send, path
         )
diff --git a/tests/fixtures.py b/tests/fixtures.py
index a4a96919..612bee99 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -39,6 +39,7 @@ EXPECTED_PLUGINS = [
         "version": None,
         "hooks": [
             "actor_from_request",
+            "asgi_wrapper",
             "extra_body_script",
             "extra_css_urls",
             "extra_js_urls",
diff --git a/tests/plugins/my_plugin.py b/tests/plugins/my_plugin.py
index 72736e84..a86e3cbf 100644
--- a/tests/plugins/my_plugin.py
+++ b/tests/plugins/my_plugin.py
@@ -137,6 +137,20 @@ def actor_from_request(datasette, request):
         return None
 
 
+@hookimpl
+def asgi_wrapper():
+    def wrap(app):
+        async def maybe_set_actor_in_scope(scope, recieve, send):
+            if b"_actor_in_scope" in scope["query_string"]:
+                scope = dict(scope, actor={"id": "from-scope"})
+                print(scope)
+            await app(scope, recieve, send)
+
+        return maybe_set_actor_in_scope
+
+    return wrap
+
+
 @hookimpl
 def permission_allowed(actor, action):
     if action == "this_is_allowed":
diff --git a/tests/test_plugins.py b/tests/test_plugins.py
index e3a234f2..245c60f7 100644
--- a/tests/test_plugins.py
+++ b/tests/test_plugins.py
@@ -534,6 +534,11 @@ def test_actor_from_request_async(app_client):
     assert {"id": "bot2", "1+1": 2} == app_client.ds._last_request.scope["actor"]
 
 
+def test_existing_scope_actor_respected(app_client):
+    app_client.get("/?_actor_in_scope=1")
+    assert {"id": "from-scope"} == app_client.ds._last_request.scope["actor"]
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "action,expected",