diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index af4a8e7..fd54a78 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -3,6 +3,8 @@ target_link_libraries(ipa-sil PRIVATE Fcitx5::Core)
 set_target_properties(ipa-sil PROPERTIES PREFIX "")
 install(TARGETS ipa-sil DESTINATION "${FCITX_INSTALL_LIBDIR}/fcitx5")
 
+set_property(TARGET ipa-sil PROPERTY CXX_STANDARD 20)
+
 # Addon config file
 # We need additional layer of conversion because we want PROJECT_VERSION in it.
 configure_file(ipa-sil-addon.conf.in ipa-sil-addon.conf)