diff --git a/server/lobbyconnection.py b/server/lobbyconnection.py
index 8127b7e91..6fe8fdc9f 100644
--- a/server/lobbyconnection.py
+++ b/server/lobbyconnection.py
@@ -929,13 +929,6 @@ async def command_game_matchmaking(self, message):
                     recoverable=True
                 )
 
-            # TODO: Remove this legacy behavior, use party instead
-            if "faction" in message:
-                party.set_factions(
-                    self.player,
-                    [Faction.from_value(message["faction"])]
-                )
-
             self.ladder_service.start_search(
                 players,
                 queue_name=queue_name,
diff --git a/tests/integration_tests/test_game.py b/tests/integration_tests/test_game.py
index d06e17451..b755b9e58 100644
--- a/tests/integration_tests/test_game.py
+++ b/tests/integration_tests/test_game.py
@@ -76,10 +76,13 @@ async def open_fa(proto):
 async def queue_player_for_matchmaking(user, lobby_server, queue_name):
     _, _, proto = await connect_and_sign_in(user, lobby_server)
     await read_until_command(proto, "game_info")
+    await proto.send_message({
+        "command": "set_party_factions",
+        "factions": ["uef"]
+    })
     await proto.send_message({
         "command": "game_matchmaking",
         "state": "start",
-        "faction": "uef",
         "queue_name": queue_name
     })
     await read_until_command(
@@ -93,27 +96,21 @@ async def queue_player_for_matchmaking(user, lobby_server, queue_name):
     return proto
 
 
-async def queue_players_for_matchmaking(lobby_server, queue_name: str = "ladder1v1"):
+async def queue_players_for_matchmaking(
+    lobby_server,
+    queue_name: str = "ladder1v1"
+):
     proto1 = await queue_player_for_matchmaking(
         ("ladder1", "ladder1"),
         lobby_server,
         queue_name
     )
-    _, _, proto2 = await connect_and_sign_in(
+    proto2 = await queue_player_for_matchmaking(
         ("ladder2", "ladder2"),
-        lobby_server
+        lobby_server,
+        queue_name
     )
 
-    await read_until_command(proto2, "game_info")
-
-    await proto2.send_message({
-        "command": "game_matchmaking",
-        "state": "start",
-        "faction": 1,  # Python client sends factions as numbers
-        "queue_name": queue_name
-    })
-    await read_until_command(proto2, "search_info", state="start")
-
     # If the players did not match, this will fail due to a timeout error
     await read_until_command(proto1, "match_found", timeout=30)
     await read_until_command(proto2, "match_found")
diff --git a/tests/integration_tests/test_teammatchmaker.py b/tests/integration_tests/test_teammatchmaker.py
index 05ecfe501..ecbba8ce1 100644
--- a/tests/integration_tests/test_teammatchmaker.py
+++ b/tests/integration_tests/test_teammatchmaker.py
@@ -38,11 +38,17 @@ async def queue_players_for_matchmaking(lobby_server):
         read_until_command(proto, "game_info") for proto in protos
     ])
 
+    await asyncio.gather(*[
+        proto.send_message({
+            "command": "set_party_factions",
+            "factions": ["uef"]
+        })
+        for proto in protos
+    ])
     await asyncio.gather(*[
         proto.send_message({
             "command": "game_matchmaking",
             "state": "start",
-            "faction": "uef",
             "queue_name": "tmm2v2"
         })
         for proto in protos
@@ -114,18 +120,27 @@ async def test_game_matchmaking_multiqueue(lobby_server):
         read_until_command(proto, "game_info") for proto in protos
     ])
 
+    await protos[0].send_message({
+        "command": "set_party_factions",
+        "factions": ["uef"]
+    })
     await protos[0].send_message({
         "command": "game_matchmaking",
         "state": "start",
-        "faction": "uef",
         "queue_name": "ladder1v1"
     })
     await read_until_command(protos[0], "search_info", state="start")
+    await asyncio.gather(*[
+        proto.send_message({
+            "command": "set_party_factions",
+            "factions": ["aeon"]
+        })
+        for proto in protos
+    ])
     await asyncio.gather(*[
         proto.send_message({
             "command": "game_matchmaking",
             "state": "start",
-            "faction": "aeon",
             "queue_name": "tmm2v2"
         })
         for proto in protos