@@ -27,10 +27,15 @@
 #import "OFException.h"
 #import "OFString.h"
 #import "OFArray.h"
 
 #import "autorelease.h"
+
+#ifdef _WIN32
+# include <errno.h>
+# include <winerror.h>
+#endif
 
 struct _Unwind_Context;
 typedef enum {
 	_URC_OK		  = 0,
 	_URC_END_OF_STACK = 5
@@ -66,10 +71,39 @@
 		return _URC_OK;
 	}
 
 	return _URC_END_OF_STACK;
 }
+
+#if defined(_WIN32) && defined(OF_HAVE_SOCKETS)
+int
+of_wsaerr_to_errno(int wsaerr)
+{
+	switch (wsaerr) {
+	case WSAEACCES:
+		return EACCES;
+	case WSAEBADF:
+		return EBADF;
+	case WSAEDISCON:
+		return EPIPE;
+	case WSAEFAULT:
+		return EFAULT;
+	case WSAEINTR:
+		return EINTR;
+	case WSAEINVAL:
+		return EINVAL;
+	case WSAENAMETOOLONG:
+		return ENAMETOOLONG;
+	case WSAENOTEMPTY:
+		return ENOTEMPTY;
+	case WSAEWOULDBLOCK:
+		return EAGAIN;
+	default:
+		return wsaerr;
+	}
+}
+#endif
 
 @implementation OFException
 + (instancetype)exception
 {
 	return [[[self alloc] init] autorelease];