diff --git a/.github/workflows/schema.yaml b/.github/workflows/schema.yaml
index c4d46a1058..880d2f6076 100644
--- a/.github/workflows/schema.yaml
+++ b/.github/workflows/schema.yaml
@@ -9,6 +9,9 @@ on:
     branches: ["develop", "release-*"]
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   validate-schema:
     name: Ensure Synapse config schema is valid