diff --git a/clang-tools-extra/clang-tidy/add_new_check.py b/clang-tools-extra/clang-tidy/add_new_check.py
--- a/clang-tools-extra/clang-tidy/add_new_check.py
+++ b/clang-tools-extra/clang-tidy/add_new_check.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 #===- add_new_check.py - clang-tidy check generator ---------*- python -*--===#
 #
@@ -16,6 +16,8 @@
 import re
 import sys
 
+assert sys.version_info >= (3,), "Requires python 3"
+
 # Adapts the module's CMakelist file. Returns 'True' if it could add a new
 # entry and 'False' if the entry already existed.
 def adapt_cmake(module_path, check_name_camel):
diff --git a/clang-tools-extra/clang-tidy/rename_check.py b/clang-tools-extra/clang-tidy/rename_check.py
--- a/clang-tools-extra/clang-tidy/rename_check.py
+++ b/clang-tools-extra/clang-tidy/rename_check.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 #===- rename_check.py - clang-tidy check renamer ------------*- python -*--===#
 #
@@ -13,6 +13,9 @@
 import io
 import os
 import re
+import sys
+
+assert sys.version_info >= (3,), "Requires python 3"
 
 def replaceInFileRegex(fileName, sFrom, sTo):
   if sFrom == sTo: