--- a/stun.cxx.ori	2010-12-18 10:53:19.216286790 +0100
+++ b/stun.cxx	2010-12-18 10:53:46.806347204 +0100
@@ -671,6 +671,10 @@
       tick |= lowtick;
 #elif defined(__GNUC__) && ( defined(__i686__) || defined(__i386__) )
       asm("rdtsc" : "=A" (tick));
+#elif defined(__GNUC__) && defined(__x86_64__)
+      unsigned _a,_d;
+      asm("rdtsc" : "=A" (_a), "=D" (_d));
+      tick = ((unsigned long long) (_a)) | (( (unsigned long long) (_d)) << 32);
 #elif defined (__SUNPRO_CC) || defined( __sparc__ )	
       tick = gethrtime();
 #elif defined(__MACH__)