diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d6e622829..381f0cd7b7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -120,6 +120,11 @@ target_include_directories(pugixml PUBLIC vendor/pugixml/)
 # xtensor header-only library
 #===============================================================================
 
+# CMake 3.13+ will complain about policy CMP0079 unless it is set explicitly
+if (NOT (CMAKE_VERSION VERSION_LESS 3.13))
+  cmake_policy(SET CMP0079 NEW)
+endif()
+
 add_subdirectory(vendor/xtl)
 add_subdirectory(vendor/xtensor)
 target_link_libraries(xtensor INTERFACE xtl)