Index: AsmJit/AsmJitConfig.h
===================================================================
--- AsmJit/AsmJitConfig.h	(revision 11)
+++ AsmJit/AsmJitConfig.h	(working copy)
@@ -49,8 +49,12 @@
 #define ASMJIT_WINDOWS 1
 #define ASMJIT_POSIX 2
 
-// HERE DEFINE YOUR OS
-// #define ASMJIT_OS ASMJIT_[WINDOWS|POSIX]
+#if defined(WINDOWS) || defined(_WIN32) || defined(_WIN64)
+#define ASMJIT_OS ASMJIT_WINDOWS
+#elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
+      defined(__NetBSD__) || defined(__DragonFly__)
+#define ASMJIT_OS ASMJIT_POSIX
+#endif
 
 #if !defined(ASMJIT_OS) || ASMJIT_OS < 1
 #error "AsmJit - Define ASMJIT_OS macro to your operating system"