diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index 697808a..518b172 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -1,6 +1,8 @@
 name: Python package
 
 on: [push, pull_request]
+permissions:
+  contents: read
 
 jobs:
   build: