diff --git a/lib/zig.h b/lib/zig.h
index 51e646485c..9d78d39f0b 100644
--- a/lib/zig.h
+++ b/lib/zig.h
@@ -10,6 +10,8 @@
 #define zig_gnuc
 #elif defined(__GNUC__)
 #define zig_gnuc
+#elif defined(__IBMC__)
+#define zig_xlc
 #elif defined(__TINYC__)
 #define zig_tinyc
 #elif defined(__slimcc__)
@@ -79,6 +81,18 @@
 #define zig_big_endian 1
 #endif
 
+#if defined(_WIN32)
+#define zig_coff
+#elif defined(__ELF__)
+#define zig_elf
+#elif defined(__MVS__)
+#define zig_goff
+#elif defined(__MACH__)
+#define zig_macho
+#elif defined(_AIX)
+#define zig_xcoff
+#endif
+
 #define zig_concat(lhs, rhs) lhs##rhs
 #define zig_expand_concat(lhs, rhs) zig_concat(lhs, rhs)
 
@@ -236,14 +250,14 @@
 #define zig_mangle_c(symbol) "_" symbol
 #endif /* zig_x86_64 */
 #else /* zig_msvc */
-#if __APPLE__
+#if defined(zig_macho)
 #define zig_mangle_c(symbol) "_" symbol
-#else /* __APPLE__ */
+#else /* zig_macho */
 #define zig_mangle_c(symbol) symbol
-#endif /* __APPLE__ */
+#endif /* zig_macho */
 #endif /* zig_msvc */
 
-#if (zig_has_attribute(alias) || defined(zig_tinyc)) && !__APPLE__
+#if (zig_has_attribute(alias) || defined(zig_tinyc)) && !defined(zig_macho)
 #define zig_export(symbol, name) __attribute__((alias(symbol)))
 #elif defined(zig_msvc)
 #define zig_export(symbol, name) ; \