diff --git a/.prettierignore b/.prettierignore
index e3915ce..cfbba01 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -12,5 +12,8 @@ target/
 !*.yaml
 !*.yml
 
+pnpm-lock.yaml
+pnpm-workspace.yaml
+
 **/vendor/*
 !**/vendor/*.md
diff --git a/package.json b/package.json
index 776eb59..8bfacd5 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
   "homepage": "https://www.artichokeruby.org",
   "bugs": "https://github.com/artichoke/ruby-strftime/issues",
   "devDependencies": {
-    "prettier": "3.6.2"
+    "prettier": "3.9.6"
   },
   "scripts": {
     "fmt": "prettier --write \"**/*\"",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 35b8c2e..c165340 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1,24 +1,24 @@
-lockfileVersion: "9.0"
+lockfileVersion: '9.0'
 
 settings:
   autoInstallPeers: true
   excludeLinksFromLockfile: false
 
 importers:
+
   .:
     devDependencies:
       prettier:
-        specifier: 3.6.2
-        version: 3.6.2
+        specifier: 3.9.6
+        version: 3.9.6
 
 packages:
-  prettier@3.6.2:
-    resolution:
-      {
-        integrity: sha512-I7AIg5boAr5R0FFtJ6rCfD+LFsWHp81dolrFD8S79U9tb8Az2nGrJncnMSnys+bpQJfRUzqs9hnA81OAA3hCuQ==,
-      }
-    engines: { node: ">=14" }
+
+  prettier@3.9.6:
+    resolution: {integrity: sha512-OpN0zzVdiaiAhxpuuj5efpIS4sY9j7bY6uR5mnj5yPzGkdkjNKSJeUThPb60Jw29QuAZgA4o+/iB49kFiaBX6g==}
+    engines: {node: '>=14'}
     hasBin: true
 
 snapshots:
-  prettier@3.6.2: {}
+
+  prettier@3.9.6: {}