diff --git a/cmake/documentation.cmake b/cmake/documentation.cmake
index a886ca35..9213c9e6 100644
--- a/cmake/documentation.cmake
+++ b/cmake/documentation.cmake
@@ -49,7 +49,7 @@ function(add_documentation targetName)
     if(NOT _args_DOXYFILE_TEMPLATE)
         set(_args_DOXYFILE_TEMPLATE Doxyfile.in)
     endif()
-    file(REAL_PATH ${_args_DOXYFILE_TEMPLATE} _doxyfileIn)
+    get_filename_component(_doxyfileIn ${_args_DOXYFILE_TEMPLATE} REALPATH)
     if(NOT EXISTS ${_doxyfileIn})
         message(FATAL_ERROR "'${_args_DOXYFILE_TEMPLATE}' does not exist")
     endif()