diff --git a/rcl_lifecycle/CMakeLists.txt b/rcl_lifecycle/CMakeLists.txt
index 46f7d76..8c13d25 100644
--- a/rcl_lifecycle/CMakeLists.txt
+++ b/rcl_lifecycle/CMakeLists.txt
@@ -46,8 +46,8 @@ call_for_each_rmw_implementation(targets GENERATE_DEFAULT)
 
 if(BUILD_TESTING)
   if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} "-std=c11")
-    set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-std=c++14")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
     add_compile_options(-Wall -Wextra -Wpedantic)
   endif()