diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a86e88d..c264c98 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,6 +2,10 @@ name: CI
 
 on: [push, pull_request]
 
+# Least-privilege: CI only checks out, builds, and tests — read is enough.
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest