diff --git a/rules/Analysis/master.rules b/rules/Analysis/master.rules
index f2fd1723a689d77f55bd57c9bfe010316a9b66ae..2d6fbf81eb693f11ba3b4c94b512b79a1f44750e 100644
--- a/rules/Analysis/master.rules
+++ b/rules/Analysis/master.rules
@@ -131,6 +131,7 @@ def analysis_stats_files_output(rtype, flag):
 
 
 def analysis_plot_files_output():
+    addon = []
     if MG and MT:
         addon = PLOT_OUTPUT_FILES['mgmt']
     elif MG: