diff --git a/.github/workflows/block-invalid-merges-main.yml b/.github/workflows/block-invalid-merges-main.yml
index 8b92b0e..622b1ba 100644
--- a/.github/workflows/block-invalid-merges-main.yml
+++ b/.github/workflows/block-invalid-merges-main.yml
@@ -5,6 +5,9 @@ on:
     branches:
       - main
 
+permissions:
+  contents: read
+
 jobs:
   check_source_branch:
     name: Prevenir Merges inválidos para o Main