diff --git a/cmake/xo_cxx.cmake b/cmake/xo_cxx.cmake
index 160a1833..d2f95936 100644
--- a/cmake/xo_cxx.cmake
+++ b/cmake/xo_cxx.cmake
@@ -42,6 +42,13 @@ macro(xo_compile_options target)
     target_copmile_options(${target} PRIVATE ${XO_COMPILE_OPTIONS})
 endmacro()
 
+# ----------------------------------------------------------------
+# use this to install typical include file subtree
+#
+macro(xo_install_include_tree)
+    install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/ DESTINATION include)
+endmacro()
+
 # ----------------------------------------------------------------
 #
 # dependency on an xo library (including header-only libraries)