diff --git a/cmake/modules/extensions.cmake b/cmake/modules/extensions.cmake
index d8ea799016a..de2aab58b1a 100644
--- a/cmake/modules/extensions.cmake
+++ b/cmake/modules/extensions.cmake
@@ -2624,11 +2624,11 @@ Please provide one of following: APPLICATION_ROOT, CONF_FILES")
       # `set(<var> CACHE)`, so let's update current scope variable to absolute
       # path from  `APPLICATION_SOURCE_DIR`.
       if(NOT IS_ABSOLUTE ${path})
-        set(abs_path ${APPLICATION_SOURCE_DIR}/${path})
         list(FIND ${ZFILE_APPLICATION_ROOT} ${path} index)
+	cmake_path(ABSOLUTE_PATH path BASE_DIRECTORY ${APPLICATION_SOURCE_DIR} NORMALIZE)
         if(NOT ${index} LESS 0)
           list(REMOVE_AT ${ZFILE_APPLICATION_ROOT} ${index})
-          list(INSERT ${ZFILE_APPLICATION_ROOT} ${index} ${abs_path})
+          list(INSERT ${ZFILE_APPLICATION_ROOT} ${index} ${path})
         endif()
       endif()
     endforeach()
@@ -2645,6 +2645,7 @@ Relative paths are only allowed with `-D${ARGV1}=<path>`")
       endif()
     endforeach()
 
+    list(REMOVE_DUPLICATES ZFILE_APPLICATION_ROOT)
     # This updates the provided argument in parent scope (callers scope)
     set(${ZFILE_APPLICATION_ROOT} ${${ZFILE_APPLICATION_ROOT}} PARENT_SCOPE)
   endif()