diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c8467f364..2bd1678e6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
   pull_request:
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   test:
     name: Python ${{ matrix.python }} on ${{ matrix.os }}