diff --git a/CMakeLists.txt b/CMakeLists.txt
index 19e29ae2..fdbd9555 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -46,6 +46,8 @@ target_include_directories(xparrow INTERFACE
     $<BUILD_INTERFACE:${XPARROW_INCLUDE_DIR}>
     $<INSTALL_INTERFACE:include>)
 
+# We do not use non-standard C++
+set_target_properties(xparrow PROPERTIES CMAKE_CXX_EXTENSIONS OFF)
 target_compile_features(xparrow INTERFACE cxx_std_20)
 
 if (BUILD_TESTS)
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 266f4efa..ecd5cd28 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -8,6 +8,7 @@
 
 cmake_minimum_required(VERSION 3.8)
 
+
 if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
     project(xtensor-test CXX)
 
@@ -33,3 +34,7 @@ set(XPARROW_TESTS
 set(test_target "test_xparrow_lib")
 add_executable(${test_target} ${XPARROW_TESTS})
 target_link_libraries(${test_target} PRIVATE xparrow doctest::doctest)
+
+# We do not use non-standard C++
+set_target_properties(${test_target} PROPERTIES CMAKE_CXX_EXTENSIONS OFF)
+target_compile_features(${test_target} PRIVATE cxx_std_20)