diff --git a/cmake_modules/SwiftenConfig.cmake b/cmake_modules/SwiftenConfig.cmake
index 5875f11590cbf81c576846d947e45ebb95b517e3..9833462e0da4845713dfa1612f3c4df5ed38a0f0 100644
--- a/cmake_modules/SwiftenConfig.cmake
+++ b/cmake_modules/SwiftenConfig.cmake
@@ -42,7 +42,7 @@ if( SWIFTEN_LIBRARY AND SWIFTEN_INCLUDE_DIR )
 
 		if("${SWIFTEN_VERSION}" STRGREATER "4" AND NOT MSVC)
 			message( STATUS "Found Swiften > 4 requesting C++11")
-			add_definitions(-std=c++11)
+			set(CMAKE_CXX_FLAGS "-std=c++11 ${CMAKE_CXX_FLAGS}")
 		endif()
 		
 		set( SWIFTEN_FOUND 1 )