diff --git a/lib/zig.h b/lib/zig.h
index ab6c30a147dc6e5e77fade618390ce420f0dcfd7..ed615e9e7210bd9fc249011f1820ed1f822ca048 100644
--- a/lib/zig.h
+++ b/lib/zig.h
@@ -114,14 +114,16 @@
 #define zig_haiku
 #elif defined(__gnu_hurd__)
 #define zig_hurd
+#elif defined(__illumos__)
+#define zig_illumos
 #elif defined(__linux__)
 #define zig_linux
 #elif defined(__NetBSD__)
 #define zig_netbsd
 #elif defined(__OpenBSD__)
 #define zig_openbsd
-#elif defined(__illumos__)
-#define zig_illumos
+#elif defined(__serenity__)
+#define zig_serenity
 #elif defined(__wasi__)
 #define zig_wasi
 #elif defined(_WIN32)