diff --git a/modules/federation/user_keys_query.cc b/modules/federation/user_keys_query.cc
index ae21df608..8e911c9b5 100644
--- a/modules/federation/user_keys_query.cc
+++ b/modules/federation/user_keys_query.cc
@@ -155,23 +155,104 @@ _query_master_keys(client &client,
 			user_id_
 		};
 
-		const m::user::room room
+		const m::user::room user_room
 		{
 			user_id
 		};
 
 		const auto event_idx
 		{
-			room.get(std::nothrow, "ircd.cross_signing.master", "")
+			user_room.get(std::nothrow, "ircd.cross_signing.master", "")
 		};
 
-		m::get(std::nothrow, event_idx, "content", [&response_keys, &user_id]
-		(const json::object &content)
+		m::get(std::nothrow, event_idx, "content", [&user_room, &user_id, &response_keys]
+		(const json::object &device_keys)
 		{
-			json::stack::member
+			json::stack::object object
 			{
-				response_keys, user_id, content
+				response_keys, user_id
 			};
+
+			for(const auto &member : device_keys)
+				if(member.first != "signatures")
+					json::stack::member
+					{
+						object, member
+					};
+
+			const json::object device_keys_sigs
+			{
+				device_keys["signatures"]
+			};
+
+			json::stack::object sigs
+			{
+				object, "signatures"
+			};
+
+			json::stack::object user_sigs
+			{
+				sigs, user_id
+			};
+
+			const json::object device_keys_user_sigs
+			{
+				device_keys_sigs[user_id]
+			};
+
+			for(const auto &member : device_keys_user_sigs)
+				json::stack::member
+				{
+					user_sigs, member
+				};
+
+			const m::room::state state
+			{
+				user_room
+			};
+
+			for(const auto &[key_id__, key] : json::object(device_keys["keys"]))
+			{
+				const auto &[algo, key_id_]
+				{
+					split(key_id__, ':')
+				};
+
+				const auto key_id(key_id_);
+				state.for_each("ircd.keys.signatures", [&user_id, &user_sigs, &key_id]
+				(const string_view &, const string_view &state_key, const auto &event_idx)
+				{
+					const auto &[target, source]
+					{
+						rsplit(state_key, '%')
+					};
+
+					if(target != key_id)
+						return true;
+
+					m::get(std::nothrow, event_idx, "content", [&user_id, &user_sigs]
+					(const json::object &device_sigs)
+					{
+						const json::object device_sigs_sigs
+						{
+							device_sigs["signatures"]
+						};
+
+						const json::object device_sigs_user_sigs
+						{
+							device_sigs_sigs[user_id]
+						};
+
+						for(const auto &member : device_sigs_user_sigs)
+							json::stack::member
+							{
+								user_sigs, member
+							};
+					});
+
+					return true;
+				});
+			}
 		});
 	}
 }