diff --git a/CMakeLists.txt b/CMakeLists.txt
index 49c8e83..fd548f1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,9 +28,7 @@ if(APPLE)
     include(AddSwift)
 endif()
 
-find_package(Qt5 COMPONENTS Widgets Network REQUIRED)
-
-message(STATUS "Qt5 framework version: ${Qt5Core_VERSION}")
+# Qt5 GUI stripped downstream: build only the Fcitx5 engine.
 
 # Get system information. WIN32 and APPLE are defined by CMake
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
@@ -146,9 +144,6 @@ if(APPLE)
 endif()
 
 add_subdirectory(src/engine)
-add_subdirectory(src/platform)
-add_subdirectory(src/frontend)
-add_subdirectory(src/shared)
 
 # uninstall target
 if(NOT TARGET uninstall)