diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a4e1394..8181dbb 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -2,6 +2,9 @@ name: Tests and checks
 
 on: push
 
+permissions:
+  contents: read
+
 jobs:
   check:
     name: Test python${{ matrix.python }} on ${{ matrix.os }}