diff --git a/urx/urrtmon.py b/urx/urrtmon.py
index 6292a45..3ff825b 100644
--- a/urx/urrtmon.py
+++ b/urx/urrtmon.py
@@ -171,7 +171,7 @@ class URRTMonitor(threading.Thread):
             if self._csys:
                 with self._csys_lock:
                     # might be a godd idea to remove dependancy on m3d
-                    tcp = self._csys * m3d.Transform(self._tcp)
+                    tcp = self._csys.inverse * m3d.Transform(self._tcp)
                 self._tcp = tcp.pose_vector
         if self._buffering:
             with self._buffer_lock: