diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1bef366c..a2d00b3d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 2.8)
 project (benchmark)
 
-find_package(Threads)
+find_package(Threads REQUIRED)
 
 set(CMAKE_CXX_FLAGS "-Wall -Werror -pedantic-errors --std=c++0x")
 set(CMAKE_CXX_FLAGS_DEBUG "-g -O0 -DDEBUG")