diff --git a/CMakeLists.txt b/CMakeLists.txt
index 211cf9b..767737d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.20...3.20)
+cmake_minimum_required(VERSION 3.18...3.20)
 
 # Global build options.
 set(CMAKE_BUILD_TYPE "Release" CACHE STRING "The type of build.")