diff --git a/ess/TraceWin.py b/ess/TraceWin.py
index 5cfefe95a0c92fa156a5a034cd5b53f429d96955..6cafd9dfb1990aebec3efe644c0a7fda57051673 100644
--- a/ess/TraceWin.py
+++ b/ess/TraceWin.py
@@ -526,7 +526,7 @@ class plt:
 
         Returns the same dst object.
         '''
-        _dst=get_dst(index)
+        _dst=self.get_dst(index)
         _dst.save(filename)
         return _dst