diff --git a/common/CMakeLists.txt b/common/CMakeLists.txt
index 3b8278755..cf2f15db1 100644
--- a/common/CMakeLists.txt
+++ b/common/CMakeLists.txt
@@ -25,6 +25,7 @@ set(common_SOURCES
     server/game/server_counter.cpp
     server/game/server_game.cpp
     server/game/server_player.cpp
+    server/game/server_spectator.cpp
     server/server.cpp
     server/server_abstractuserinterface.cpp
     server/server_database_interface.cpp