diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 0df9d9ca..df51dda0 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -6,6 +6,9 @@ on:
   # Allow manually triggering the workflow.
   workflow_dispatch:
 
+permissions:
+  contents: read # to fetch code (actions/checkout)
+
 jobs:
 
   coding-standard: