diff --git a/cmake_configure.cmake b/cmake_configure.cmake
index d387e5bf..4a4bdcc9 100644
--- a/cmake_configure.cmake
+++ b/cmake_configure.cmake
@@ -2,6 +2,7 @@ add_library(rw_interface INTERFACE)
 add_library(openrw::interface ALIAS rw_interface)
 
 # target_compile_features(rw_interface INTERFACE cxx_std_14) is not supported by CMake 3.2
+set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)