diff --git a/tools/custom_check.py b/tools/custom_check.py
index 6bd5ea5..70b4bdd 100644
--- a/tools/custom_check.py
+++ b/tools/custom_check.py
@@ -165,8 +165,7 @@ def build_custom_checkers(by_lang):
         # This rule might give false positives in virtualenv setup files which should be excluded,
         # and comments which should be rewritten to avoid use of "python2", "python3", etc.
         {'pattern': 'python[23]',
-         'exclude': set(['tools/provision']),
-         'include_only': set(['zulip/', 'tools/', 'zulip_botserver/']),
+         'include_only': set(['zulip/', 'zulip_botserver/']),
          'description': 'Explicit python invocations should not include a version'},
         {'pattern': '__future__',
          'include_only': set(['zulip_bots/zulip_bots/bots/']),
diff --git a/tools/test-bots b/tools/test-bots
index 4792ce5..496c3aa 100755
--- a/tools/test-bots
+++ b/tools/test-bots
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from os.path import dirname, basename
 from importlib import import_module
diff --git a/tools/test-lib b/tools/test-lib
index a933fd4..7c1bc2e 100755
--- a/tools/test-lib
+++ b/tools/test-lib
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys