diff --git a/script/gen_constants_cpp.py b/script/gen_constants_cpp.py
index a6b2c6203d..1c33f8db6a 100755
--- a/script/gen_constants_cpp.py
+++ b/script/gen_constants_cpp.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 #
 # Copyright (c) 2015 Microsoft Corporation. All rights reserved.
diff --git a/script/gen_tokens_cpp.py b/script/gen_tokens_cpp.py
index 16e4117721..5d354479f5 100755
--- a/script/gen_tokens_cpp.py
+++ b/script/gen_tokens_cpp.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 #
 # Copyright (c) 2015 Microsoft Corporation. All rights reserved.
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 72538abebd..a5d9ff911f 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -407,7 +407,7 @@ endforeach(T)
 
 # Lint test suite and parts of the repository.
 # Must not run in parallel with any other tests that may create or delete files.
-add_test(NAME lint.py COMMAND python lint.py WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+add_test(NAME lint.py COMMAND python3 lint.py WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 set_tests_properties(lint.py PROPERTIES RUN_SERIAL TRUE)
 
 add_test_pile(compile *.lean BENCH PART2)
diff --git a/tests/lint.py b/tests/lint.py
index 25c02cf8f3..d1ecc43762 100755
--- a/tests/lint.py
+++ b/tests/lint.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
@@ -190,11 +190,10 @@ for file in Path().glob("**/run_bench"):
         nag("has env_test.sh", file)
 
 
-# File confusion by case insensitive filesystems,
-# applies to entire repository
+# File confusion by case insensitive filesystems
 
 seen: set[str] = set()
-for file in Path("..").glob("**/*"):
+for file in Path().glob("**/*"):
     path = str(file).lower()
     if path in seen:
         nag("case sensitive", file)
diff --git a/tests/util.sh b/tests/util.sh
index 0f5e1634fb..2244062112 100644
--- a/tests/util.sh
+++ b/tests/util.sh
@@ -1,4 +1,4 @@
-set -eu
+set -e
 
 DIFF="diff -au --strip-trailing-cr --color=always"
 ulimit -S -s ${TEST_STACK_SIZE:-8192}