Restored use of CMake Threads package.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 232a106..f879b06 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -30,6 +30,9 @@
     find_package(OpenGL REQUIRED)
 endif()
 
+set(CMAKE_THREAD_PREFER_PTHREAD OFF)
+find_package(Threads REQUIRED)
+
 #--------------------------------------------------------------------
 # Enable all warnings on GCC, regardless of OS
 #--------------------------------------------------------------------