diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d61fe58b..e11c84949 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -199,7 +199,7 @@ if(MSVC)
 	add_definitions(-D_CRT_SECURE_NO_WARNINGS -D_SCL_SECURE_NO_WARNINGS)
 	add_definitions(/wd4251 /wd4275 /wd4251 /wd4661) # Disable non-DLL-exported base class and other warnings
 else()
-#    list(APPEND CMAKE_CXX_FLAGS "-std=c++11") 
+    list(APPEND CMAKE_CXX_FLAGS "-std=c++11") # FIXME: we should probably avoid these extensions
 endif()
 
 if(GTSAM_ENABLE_CONSISTENCY_CHECKS)