This is a backport from
https://github.com/arx/ArxLibertatis/commit/60e43c3cbf3fb0aa10cc3092b2512ccebb60b80d

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,6 +11,11 @@
 	endif()
 else()
 	cmake_minimum_required(VERSION 2.8)
+	if(CMAKE_VERSION VERSION_GREATER 3.4)
+		cmake_policy(VERSION 3.4)
+	else()
+		cmake_policy(VERSION ${CMAKE_VERSION})
+	 endif()
 endif()