diff --git a/examples/lkat_trace.py b/examples/lkat_trace.py
index e8b7a4b4ca1795d492f53b2625eaa34e09b51d46..75e6b60c8e9e28ca93ead5e2b247ef345036458f 100644
--- a/examples/lkat_trace.py
+++ b/examples/lkat_trace.py
@@ -11,7 +11,7 @@ pd circ n3
 noxaxis
 maxtem 2
 
-attr m1 Rc -1000
+attr m1 Rc 0
 attr m2 Rc 1000 
 cav c1 m1 n3 m2 n4
 """
diff --git a/pykat/finesse.py b/pykat/finesse.py
index c7647e4c8f3619a87df1e2932c98979a706943a0..82d018c5787e67bc46edef8e8bf26dc6b26f5258 100644
--- a/pykat/finesse.py
+++ b/pykat/finesse.py
@@ -1169,7 +1169,8 @@ class kat(object):
         p.start()
         p.join()
 
-        return trace_info
+        # return a local copy of the trace information dictionary
+        return dict(trace_info)
     
     def __add_detector(self, det):