diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index de1e1fe18..07e21ef43 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,6 +6,9 @@ on:
   push:
     branches: [master]
 
+permissions:
+  contents: read  #  to fetch code (actions/checkout)
+
 jobs:
   build_and_test:
     strategy: