diff --git a/perf/cairo-perf-posix.c b/perf/cairo-perf-posix.c
index 8bf78cec5..8bc4e092b 100644
--- a/perf/cairo-perf-posix.c
+++ b/perf/cairo-perf-posix.c
@@ -70,9 +70,9 @@
 static inline cairo_perf_ticks_t
 oil_profile_stamp_rdtsc (void)
 {
-    uint64_t ts;
-    __asm__ __volatile__("rdtsc\n" : "=A" (ts));
-    return ts;
+    unsigned a, d; 
+    __asm__ __volatile__("rdtsc" : "=a" (a), "=d" (d)); 
+    return ((uint64_t)a) | (((uint64_t)d) << 32); 
 }
 #define OIL_STAMP oil_profile_stamp_rdtsc
 #endif