diff --git a/ci/erlang.yml b/ci/erlang.yml
index 25cb893..3bebb1f 100644
--- a/ci/erlang.yml
+++ b/ci/erlang.yml
@@ -6,10 +6,14 @@ on:
   pull_request:
     branches: [ $default-branch ]
 
+permissions: read-all
+
 jobs:
 
   build:
 
+    permissions:
+      contents: read # for actions/checkout to fetch code
     runs-on: ubuntu-latest
 
     container: