diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4e106e3b..424d2e64 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,8 +5,13 @@ on:
     branches: [master]
   schedule:
   - cron: '3 3 3 * *'
+permissions:
+  contents: read
+
 jobs:
   ci:
+    permissions:
+      contents: none
     name: CI
     needs: [test, check, docs, rustfmt, clippy]
     runs-on: ubuntu-latest
diff --git a/.github/workflows/post-release.yml b/.github/workflows/post-release.yml
index ee516150..e7334fe1 100644
--- a/.github/workflows/post-release.yml
+++ b/.github/workflows/post-release.yml
@@ -3,8 +3,13 @@ on:
   push:
     tags:
     - "v*"
+permissions:
+  contents: read
+
 jobs:
   create-release:
+    permissions:
+      contents: write  # for actions/create-release to create a release
     name: create-release
     runs-on: ubuntu-latest
     outputs:
diff --git a/.github/workflows/rust-next.yml b/.github/workflows/rust-next.yml
index 50a46298..d3866f2d 100644
--- a/.github/workflows/rust-next.yml
+++ b/.github/workflows/rust-next.yml
@@ -2,6 +2,9 @@ name: rust-next
 on:
   schedule:
   - cron: '3 3 3 * *'
+permissions:
+  contents: read
+
 jobs:
   test:
     name: Test
diff --git a/.github/workflows/spelling.yml b/.github/workflows/spelling.yml
index 8d296517..3eac2073 100644
--- a/.github/workflows/spelling.yml
+++ b/.github/workflows/spelling.yml
@@ -1,6 +1,9 @@
 name: Spelling
 on: [pull_request]
 
+permissions:
+  contents: read
+
 jobs:
   spelling:
     name: Spell Check with Typos