diff --git a/cmake/add_dependency.cmake b/cmake/add_dependency.cmake
index e292318b2e6bee206a76b5b9d076f589374928c8..3cabac99581f26f53083c7ed08c96a779a3f43ff 100644
--- a/cmake/add_dependency.cmake
+++ b/cmake/add_dependency.cmake
@@ -39,6 +39,7 @@ FUNCTION(add_dependency dependency_project_name required_version)
   SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${dependency_project_name}_CXX_FLAGS}" PARENT_SCOPE)
   SET(${dependency_project_name}_LIBRARIES ${${dependency_project_name}_LIBRARIES} PARENT_SCOPE)
   SET(${dependency_project_name}_LINK_FLAGS ${${dependency_project_name}_LINK_FLAGS} PARENT_SCOPE)
+  SET(${dependency_project_name}_CXX_FLAGS ${${dependency_project_name}_CXX_FLAGS} PARENT_SCOPE)
 
 ENDFUNCTION(add_dependency)