diff --git a/nupic/research/monitor_mixin/trace.py b/nupic/research/monitor_mixin/trace.py
index <HASH>..<HASH> 100644
--- a/nupic/research/monitor_mixin/trace.py
+++ b/nupic/research/monitor_mixin/trace.py
@@ -99,7 +99,7 @@ class IndicesTrace(Trace):
 
   @staticmethod
   def prettyPrintDatum(datum):
-    return str(list(datum))
+    return str(sorted(list(datum)))
Sort the indices while pretty-printing a trace