diff --git a/lualib/CMakeLists.txt b/lualib/CMakeLists.txt
index b1bf6e4..3f97344 100644
--- a/lualib/CMakeLists.txt
+++ b/lualib/CMakeLists.txt
@@ -26,3 +26,9 @@ target_include_directories(lualib
     ${PUBLIC_INCLUDES}
   PRIVATE
     ${CMAKE_CURRENT_BINARY_DIR})
+
+if (APPLE)
+  target_compile_definitions(lualib PUBLIC LUA_USE_MACOSX)
+elseif (UNIX)
+  target_compile_definitions(lualib PUBLIC LUA_USE_LINUX)
+endif()