diff --git a/hw/xfree86/x86emu/ops2.c b/hw/xfree86/x86emu/ops2.c
index 7b0156aaa..8c6c53539 100644
--- a/hw/xfree86/x86emu/ops2.c
+++ b/hw/xfree86/x86emu/ops2.c
@@ -63,6 +63,40 @@ static void x86emuOp2_illegal_op(
 
 #define xorl(a,b)   ((a) && !(b)) || (!(a) && (b))
 
+/****************************************************************************
+REMARKS:
+Handles opcode 0x0f,0x31
+****************************************************************************/
+static void x86emuOp2_rdtsc(u8 X86EMU_UNUSED(op2))
+{
+#ifdef __HAS_LONG_LONG__
+    static u64 counter = 0;
+#else
+    static u32 counter = 0;
+#endif
+
+    counter += 0x10000;
+
+    /* read timestamp counter */
+    /*
+     * Note that instead of actually trying to accurately measure this, we just
+     * increase the counter by a fixed amount every time we hit one of these
+     * instructions.  Feel free to come up with a better method.
+     */
+    START_OF_INSTR();
+    DECODE_PRINTF("RDTSC\n");
+    TRACE_AND_STEP();
+#ifdef __HAS_LONG_LONG__
+    M.x86.R_EAX = counter & 0xffffffff;
+    M.x86.R_EDX = counter >> 32;
+#else
+    M.x86.R_EAX = counter;
+    M.x86.R_EDX = 0;
+#endif
+    DECODE_CLEAR_SEGOVR();
+    END_OF_INSTR();
+}
+
 /****************************************************************************
 REMARKS:
 Handles opcode 0x0f,0x80-0x8F
@@ -2580,7 +2614,7 @@ void (*x86emu_optab2[256])(u8) =
 /*  0x2f */ x86emuOp2_illegal_op,
 
 /*  0x30 */ x86emuOp2_illegal_op,
-/*  0x31 */ x86emuOp2_illegal_op,
+/*  0x31 */ x86emuOp2_rdtsc,
 /*  0x32 */ x86emuOp2_illegal_op,
 /*  0x33 */ x86emuOp2_illegal_op,
 /*  0x34 */ x86emuOp2_illegal_op,