diff --git a/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs b/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
index 71c6049167..feb026946f 100644
--- a/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
+++ b/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
@@ -146,6 +146,11 @@ namespace OpenRA.Mods.Common.Server
 						if (slot.Closed || server.LobbyInfo.ClientInSlot(s) != null)
 							return false;
 
+						// If the previous slot had a locked spawn then we must not carry that to the new slot
+						var oldSlot = client.Slot != null ? server.LobbyInfo.Slots[client.Slot] : null;
+						if (oldSlot != null && oldSlot.LockSpawn)
+							client.SpawnPoint = 0;
+
 						client.Slot = s;
 						S.SyncClientToPlayerReference(client, server.MapPlayers.Players[s]);
 
@@ -870,6 +875,22 @@ namespace OpenRA.Mods.Common.Server
 							return true;
 						}
 
+						// Check if any other slot has locked the requested spawn
+						if (spawnPoint > 0)
+						{
+							var spawnLockedByAnotherSlot = server.LobbyInfo.Slots.Where(ss => ss.Value.LockSpawn).Any(ss =>
+							{
+								var pr = PlayerReferenceForSlot(server, ss.Value);
+								return pr != null && pr.Spawn == spawnPoint;
+							});
+
+							if (spawnLockedByAnotherSlot)
+							{
+								server.SendOrderTo(conn, "Message", "The spawn point is locked to another player slot.");
+								return true;
+							}
+						}
+
 						targetClient.SpawnPoint = spawnPoint;
 						server.SyncLobbyClients();
 						return true;
@@ -1032,5 +1053,13 @@ namespace OpenRA.Mods.Common.Server
 			if (client.Slot == null || !server.LobbyInfo.Slots[client.Slot].LockColor)
 				client.Color = SanitizePlayerColor(server, client.Color, client.Index);
 		}
+
+		public PlayerReference PlayerReferenceForSlot(S server, Session.Slot slot)
+		{
+			if (slot == null)
+				return null;
+
+			return server.MapPlayers.Players[slot.PlayerReference];
+		}
 	}
 }