diff --git a/sources.cmake b/sources.cmake
index 7eb60af16..d104ee938 100644
--- a/sources.cmake
+++ b/sources.cmake
@@ -117,6 +117,7 @@ src/karts/skidding.cpp
 src/karts/skidding_properties.cpp
 src/main.cpp
 src/main_loop.cpp
+src/modes/demo_world.cpp
 src/modes/follow_the_leader.cpp
 src/modes/game_tutorial.cpp
 src/modes/linear_world.cpp
@@ -359,6 +360,7 @@ src/karts/rescue_animation.hpp
 src/karts/skidding.hpp
 src/karts/skidding_properties.hpp
 src/main_loop.hpp
+src/modes/demo_world.hpp
 src/modes/follow_the_leader.hpp
 src/modes/game_tutorial.hpp
 src/modes/linear_world.hpp