diff --git a/.github/workflows/apidiff.yaml b/.github/workflows/apidiff.yaml
index ca2e787..37c0b5f 100644
--- a/.github/workflows/apidiff.yaml
+++ b/.github/workflows/apidiff.yaml
@@ -4,6 +4,8 @@ on:
   pull_request:
     branches:
       - master
+permissions:
+  contents: read
 jobs:
   compat:
     runs-on: ubuntu-latest