diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b85fd3d..e705a27 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
   pull_request:
     types: [opened, reopened, review_requested, synchronize]
 
+permissions:
+  contents: read
+
 jobs:
   run-tests:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/docker-compose-for-compiler-developers.yml b/.github/workflows/docker-compose-for-compiler-developers.yml
index bcfda2b..a3ce40f 100644
--- a/.github/workflows/docker-compose-for-compiler-developers.yml
+++ b/.github/workflows/docker-compose-for-compiler-developers.yml
@@ -5,6 +5,9 @@ on:
   pull_request:
     types: [opened, reopened, review_requested, synchronize]
 
+permissions:
+  contents: read
+
 jobs:
   run-tests:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/docker-compose.yml b/.github/workflows/docker-compose.yml
index b0622a7..b01cdd2 100644
--- a/.github/workflows/docker-compose.yml
+++ b/.github/workflows/docker-compose.yml
@@ -5,6 +5,9 @@ on:
   pull_request:
     types: [opened, reopened, review_requested, synchronize]
 
+permissions:
+  contents: read
+
 jobs:
   run-tests:
     runs-on: ubuntu-latest