link to pthread library using CMake (in CLion)

Question

I've looked all over and I can't figure out how to get CLion to link the lpthread library. I know that w/ gcc you can just type -lpthread, but I need to do some debugging in CLion.

Here's my current CMakeLists file:

cmake_minimum_required(VERSION 3.3)

project(lab4)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")

include_directories(/usr/include/)
link_directories(/usr/include/)

set(SOURCE_FILES lab4_v2.c)
add_executable(lab4 ${SOURCE_FILES})