diff --git a/c-programming/mem/safe_mem.h b/c-programming/mem/safe_mem.h
index 045a20a..1b1f47e 100644
--- a/c-programming/mem/safe_mem.h
+++ b/c-programming/mem/safe_mem.h
@@ -39,7 +39,7 @@
 
 # include <windows.h>
 # define secure_erase SecureZeroMemory
-#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
+#elif __STDC_LIB_EXT1__
 # define NO_SECURE_ERASE_WARRANTY 0
 # define SECURE_ERASE_WARRANTY "C11+: memset_s"