diff --git a/apps/twnlua/CMakeLists.txt b/apps/twnlua/CMakeLists.txt
index 1f4317d..95135cf 100644
--- a/apps/twnlua/CMakeLists.txt
+++ b/apps/twnlua/CMakeLists.txt
@@ -11,7 +11,7 @@ add_subdirectory($ENV{TWNROOT} $ENV{TWNBUILDDIR})
 add_custom_command(
    OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/luabind.c
    COMMAND ${PYTHON3} ${CMAKE_CURRENT_SOURCE_DIR}/bindgen.py $ENV{TWNROOT}/share/twn_api.json > ${CMAKE_CURRENT_SOURCE_DIR}/luabind.c
-   DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bindgen.py
+   DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bindgen.py $ENV{TWNROOT}/share/twn_api.json
 )