diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1b90ed07..9cbc92ff 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -2,6 +2,7 @@ set(SELF_LIB refcnt)
 set(SELF_SRCS Refcounted.cpp Displayable.cpp)
 
 xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
+xo_install_include_tree3(include/xo/cxxutil)
 
 # NOTE:
 # dependency set here must be kept consistent with refcnt/cmake/refcntConfig.cmake.in