Linux c++ compiling warning: scoped enums only available with -std=c++11 or -std=gnu++11

I'm trying to compile my C++ code in linux but I get the following error:

warning: scoped enums only available with -std=c++11 or -std=gnu++11 [enabled by default] 

I use the flags

-std=c++11 -g -Wall -O2 -pedantic -pthread

c++11 is in there as specified but still get that warning.
The enum contains:

enum class STATE { ONE, TWO};