diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 60fcf10..fb31c6e 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -29,7 +29,7 @@ include(CheckCXXCompilerFlag)
 
 string(TOUPPER "${CMAKE_BUILD_TYPE}" U_CMAKE_BUILD_TYPE)
 
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++20")
 
 if(MSVC)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc /MP /bigobj")