diff --git a/.github/workflows/ci-tests.yml b/.github/workflows/ci-tests.yml
index 30fc230b..bfe930a2 100644
--- a/.github/workflows/ci-tests.yml
+++ b/.github/workflows/ci-tests.yml
@@ -12,6 +12,9 @@ on:
       - "tests/**"
       - "pyproject.toml"
 
+permissions:
+  contents: read
+
 jobs:
   test:
     name: pytest
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 94e0b5c5..e8c1a85f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+permissions:
+  contents: read
+
 jobs:
   lint-workflows:
     name: Validate GitHub Actions workflows
diff --git a/.github/workflows/smoke-test-install.yml b/.github/workflows/smoke-test-install.yml
index 3a27e6df..59a4d5cb 100644
--- a/.github/workflows/smoke-test-install.yml
+++ b/.github/workflows/smoke-test-install.yml
@@ -5,6 +5,9 @@ on:
     - cron: "0 6 * * *" # Daily at 06:00 UTC
   workflow_dispatch:
 
+permissions:
+  contents: none
+
 jobs:
   smoke-test:
     name: Install and compile all workflows