diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index be075c6..1361f7d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,7 +3,6 @@ name: CI
 on:
   push:
     branches-ignore: ["main"]
-  pull_request:
 
 jobs:
   build:
diff --git a/_config.yml b/_config.yml
index 8b9391e..b6a3221 100644
--- a/_config.yml
+++ b/_config.yml
@@ -39,6 +39,12 @@ kramdown:
 plugins:
   - jekyll-sitemap
 
+# Jekyll defaults to `no-store`, which prevents testing the browser's
+# back/forward cache. Always revalidate local responses without disabling it.
+webrick:
+  headers:
+    Cache-Control: no-cache
+
 exclude:
   - Gemfile
   - Gemfile.lock