diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a125347..a1cf3f0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
         branches: [ main ]
     pull_request:
 
+permissions:
+    contents: read
+
 jobs:
     check-cs:
         name: Coding Style