diff --git a/federation/entities/diaspora/mappers.py b/federation/entities/diaspora/mappers.py
index 5f29e63..bcd5f0d 100644
--- a/federation/entities/diaspora/mappers.py
+++ b/federation/entities/diaspora/mappers.py
@@ -109,7 +109,7 @@ def element_to_objects(
         # If relayable, fetch sender key for validation
         entity._xml_tags = get_element_child_info(element, "tag")
         if sender_key_fetcher:
-            entity._sender_key = sender_key_fetcher(entity.handle)
+            entity._sender_key = sender_key_fetcher(entity.actor_id)
         else:
             profile = retrieve_and_parse_profile(entity.handle)
             if profile:
diff --git a/federation/protocols/diaspora/magic_envelope.py b/federation/protocols/diaspora/magic_envelope.py
index 42e9871..f4bac79 100644
--- a/federation/protocols/diaspora/magic_envelope.py
+++ b/federation/protocols/diaspora/magic_envelope.py
@@ -6,7 +6,7 @@ from Crypto.Signature import PKCS1_v1_5
 from lxml import etree
 
 from federation.exceptions import SignatureVerificationError
-from federation.utils.diaspora import fetch_public_key
+from federation.utils.diaspora import fetch_public_key, generate_diaspora_profile_id
 from federation.utils.text import decode_if_bytes
 
 NAMESPACE = "http://salmon-protocol.org/ns/magic-env"
@@ -73,7 +73,8 @@ class MagicEnvelope:
 
     def fetch_public_key(self):
         if self.sender_key_fetcher:
-            self.public_key = self.sender_key_fetcher(self.author_handle)
+            actor_id = generate_diaspora_profile_id(self.author_handle)
+            self.public_key = self.sender_key_fetcher(actor_id)
             return
         self.public_key = fetch_public_key(self.author_handle)
 
diff --git a/federation/tests/entities/diaspora/test_mappers.py b/federation/tests/entities/diaspora/test_mappers.py
index e15bd12..35ae261 100644
--- a/federation/tests/entities/diaspora/test_mappers.py
+++ b/federation/tests/entities/diaspora/test_mappers.py
@@ -209,7 +209,7 @@ class TestDiasporaEntityMappersReceive:
     def test_element_to_objects_calls_sender_key_fetcher(self, mock_validate):
         mock_fetcher = Mock()
         message_to_objects(DIASPORA_POST_COMMENT, "diaspora://alice@alice.diaspora.example.org/profile/", mock_fetcher)
-        mock_fetcher.assert_called_once_with("alice@alice.diaspora.example.org")
+        mock_fetcher.assert_called_once_with("diaspora://alice@alice.diaspora.example.org/profile/")
 
     @patch("federation.entities.diaspora.mappers.DiasporaComment._validate_signatures")
     @patch("federation.entities.diaspora.mappers.retrieve_and_parse_profile")
diff --git a/federation/tests/protocols/diaspora/test_magic_envelope.py b/federation/tests/protocols/diaspora/test_magic_envelope.py
index 278007c..018a206 100644
--- a/federation/tests/protocols/diaspora/test_magic_envelope.py
+++ b/federation/tests/protocols/diaspora/test_magic_envelope.py
@@ -45,7 +45,7 @@ class TestMagicEnvelope:
         mock_fetcher = Mock(return_value="public key")
         env = MagicEnvelope(author_handle="spam@eggs", sender_key_fetcher=mock_fetcher)
         env.fetch_public_key()
-        mock_fetcher.assert_called_once_with("spam@eggs")
+        mock_fetcher.assert_called_once_with("diaspora://spam@eggs/profile/")
         assert not mock_fetch.called
 
     @patch("federation.protocols.diaspora.magic_envelope.fetch_public_key", autospec=True)