diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0ae80af..a2a9d22 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
   pull_request:
   schedule: [cron: "40 1 * * *"]
 
+permissions:
+  contents: read
+
 env:
   RUSTFLAGS: -Dwarnings