diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index d8a9bf352..27c2eef82 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -311,9 +311,6 @@ declare_project(thirdparty/luasec DEPENDS luajit luasocket openssl)
 # luasocket
 declare_project(thirdparty/luasocket DEPENDS luajit)
 
-# lunajson
-declare_project(thirdparty/lunajson)
-
 # lunasvg
 declare_project(thirdparty/lunasvg EXCLUDE_FROM_ALL)
 
diff --git a/thirdparty/lunajson/CMakeLists.txt b/thirdparty/lunajson/CMakeLists.txt
deleted file mode 100644
index 72e23bde3..000000000
--- a/thirdparty/lunajson/CMakeLists.txt
+++ /dev/null
@@ -1,11 +0,0 @@
-# Build in source tree.
-set(BINARY_DIR ${SOURCE_DIR})
-
-append_install_commands(INSTALL_CMD src/lunajson.lua DESTINATION common)
-append_tree_install_commands(INSTALL_CMD src/lunajson common/lunajson)
-
-external_project(
-    DOWNLOAD URL 50236a29ac4222ce6a83dc4de757666a
-    https://github.com/grafi-tt/lunajson/archive/refs/tags/1.2.3.tar.gz
-    INSTALL_COMMAND ${INSTALL_CMD}
-)