diff --git a/CMakeLists.txt b/CMakeLists.txt
index 618adf2..8c81460 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,6 @@ CMAKE_MINIMUM_REQUIRED(VERSION 3.15)
 SET(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 SET(CMAKE_C_STANDARD 99)
-SET(CMAKE_C_EXTENSIONS OFF) # actually use c99, *not* gnu99
 
 IF(CMAKE_C_COMPILER_ID MATCHES "Clang" OR CMAKE_COMPILER_ID MATCHES "GNU")
   IF(UNIX AND CMAKE_GENERATOR STREQUAL "Ninja")