diff --git a/unitree_legged_real/CMakeLists.txt b/unitree_legged_real/CMakeLists.txt
index d7c24e7..9c1536a 100755
--- a/unitree_legged_real/CMakeLists.txt
+++ b/unitree_legged_real/CMakeLists.txt
@@ -22,7 +22,7 @@ set(LEGGED_SDK_NAME -pthread libunitree_legged_sdk_${ARCH}.so lcm)
 set(EXTRA_LIBS ${LEGGED_SDK_NAME} lcm)
 
 
-set(CMAKE_CXX_FLAGS "-O3 -fPIC")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O3 -fPIC")