diff --git a/hokuyo_estimation/CMakeLists.txt b/hokuyo_estimation/CMakeLists.txt
index a6d3b3587..59b5ceb21 100644
--- a/hokuyo_estimation/CMakeLists.txt
+++ b/hokuyo_estimation/CMakeLists.txt
@@ -25,7 +25,7 @@ find_package(catkin REQUIRED COMPONENTS
 
 ## System dependencies are found with CMake's conventions
 # find_package(Boost REQUIRED COMPONENTS system)
-set(CMAKE_CXX_FLAGS "-std=c++11")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 
 find_package(OpenCV REQUIRED)
 message(WARNING "OPENCV ${OpenCV_VERSION} FOUND")