diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 16a50a7..6f16cc3 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -1,4 +1,6 @@
 name: CI
+permissions:
+  contents: read
 
 on: [push]