diff --git a/radio/src/targets/simu/CMakeLists.txt b/radio/src/targets/simu/CMakeLists.txt
index a5dec7ecb..f91c9ce94 100644
--- a/radio/src/targets/simu/CMakeLists.txt
+++ b/radio/src/targets/simu/CMakeLists.txt
@@ -17,7 +17,14 @@ if(Qt5Widgets_FOUND)
   set(SIMULATOR_FLAVOUR opentx-${FLAVOUR})
   set(SIMULATOR_TARGET ${SIMULATOR_FLAVOUR}-simulator)
   add_definitions(-DSIMULATOR_FLAVOUR="${SIMULATOR_FLAVOUR}")
-  add_definitions(-std=gnu++11)
+
+  if (${CMAKE_VERSION} VERSION_LESS 3.1.0})
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
+    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -std=gnu++11")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -std=gnu++11")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -std=gnu++11")
+  endif()
+
   include_directories(${COMPANION_SRC_DIRECTORY} ${COMPANION_SRC_DIRECTORY}/simulation)
   add_library(${SIMULATOR_TARGET} SHARED ${SIMU_SRC} opentxsimulator.cpp)
   add_dependencies(${SIMULATOR_TARGET} ${FIRMWARE_DEPENDENCIES})