diff --git a/processing/post/averageDown.py b/processing/post/averageDown.py
index 6d436435b..507d1338c 100755
--- a/processing/post/averageDown.py
+++ b/processing/post/averageDown.py
@@ -80,7 +80,7 @@ if filenames == []:
 else:
   for name in filenames:
     if os.path.exists(name):
-      files.append({'name':name, 'input':open(name), 'output':open(prefix+'_'+name,'w')})
+      files.append({'name':name, 'input':open(name), 'output':open(os.path.dirname(name)+os.sep+prefix+'_'+os.path.basename(name),'w')})
 
 
 # ------------------------------------------ loop over input files ---------------------------------------