diff --git a/tools/generate-grenade-plugins-list.py b/tools/generate-grenade-plugins-list.py
index a0743041..aeb6eb30 100644
--- a/tools/generate-grenade-plugins-list.py
+++ b/tools/generate-grenade-plugins-list.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 # Copyright 2016 Hewlett Packard Enterprise Development Company, L.P.
 #
diff --git a/tools/outfilter.py b/tools/outfilter.py
index 9686a387..20e19d5b 100755
--- a/tools/outfilter.py
+++ b/tools/outfilter.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright 2014 Hewlett-Packard Development Company, L.P.
 #
@@ -50,7 +50,7 @@ def main():
     opts = get_options()
     outfile = None
     if opts.outfile:
-        outfile = open(opts.outfile, 'a', 0)
+        outfile = open(opts.outfile, 'a', buffering=1)
 
     # otherwise fileinput reprocess args as files
     sys.argv = []