diff --git a/c-programming/mem/safe_mem.h b/c-programming/mem/safe_mem.h
index 92a4640..450e99b 100644
--- a/c-programming/mem/safe_mem.h
+++ b/c-programming/mem/safe_mem.h
@@ -32,8 +32,7 @@ typedef unsigned char byte;
     malloc((size_t) (nmemb) * (size_t) (size))
 
 /* secure_erase(dest, count): erases memory explicitly */
-#if defined(__OpenBSD__) && !defined(SAFE_MEM_OLD_BSD) || \
-    defined(__FreeBSD__) && !defined(SAFE_MEM_OLD_BSD)
+#if (defined(__OpenBSD__) || defined(__FreeBSD__)) && !defined(SAFE_MEM_OLD_BSD)
 # define NO_SECURE_ERASE_WARRANTY 0
 # define SECURE_ERASE_WARRANTY "OpenBSD/FreeBSD: explicit_bzero"