diff --git a/package-lock.json b/package-lock.json
index 370e9090c..dd7886c30 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21,7 +21,7 @@
         "@octokit/auth-action": "^5.0.0",
         "@octokit/auth-app": "^7.0.0",
         "@octokit/auth-oauth-app": "^8.0.0",
-        "@octokit/tsconfig": "^3.0.0",
+        "@octokit/tsconfig": "^4.0.0",
         "@sinonjs/fake-timers": "^13.0.0",
         "@types/jest": "^29.0.0",
         "@types/lolex": "^5.1.0",
@@ -1146,10 +1146,11 @@
       }
     },
     "node_modules/@octokit/tsconfig": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/@octokit/tsconfig/-/tsconfig-3.0.0.tgz",
-      "integrity": "sha512-tQLwgXYfBq9iUbOq26kWCzsJL6DY7qjOLzqcg5tCFQ4ob48H47iX98NudHW7S5OQ/fpSKYJhb3eQehyBNzYjfA==",
-      "dev": true
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/@octokit/tsconfig/-/tsconfig-4.0.0.tgz",
+      "integrity": "sha512-hRd6UhX19m+8WhfrEpNLtm9TjuizYSG/dE0a+ivU71ylSxABVe4mEK+JMAGdjj6/gIQ+5DPegTPofi4P8VC5IA==",
+      "dev": true,
+      "license": "MIT"
     },
     "node_modules/@octokit/types": {
       "version": "13.5.0",
diff --git a/package.json b/package.json
index 848d06706..ad70deece 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "lint:fix": "prettier --write '{src,test}/**/*.{ts,md}' README.md package.json",
     "pretest": "npm run -s lint",
     "test": "vitest --coverage",
-    "test:typescript": "npx tsc --noEmit --declaration --noUnusedLocals --module node16 --moduleResolution node16 --allowImportingTsExtensions test/typescript-validate.ts"
+    "test:typescript": "npx tsc --noEmit --declaration --noUnusedLocals --module node16 --moduleResolution node16 --allowImportingTsExtensions --exactOptionalPropertyTypes --strict test/typescript-validate.ts"
   },
   "repository": "github:octokit/core.js",
   "keywords": [
@@ -38,7 +38,7 @@
     "@octokit/auth-action": "^5.0.0",
     "@octokit/auth-app": "^7.0.0",
     "@octokit/auth-oauth-app": "^8.0.0",
-    "@octokit/tsconfig": "^3.0.0",
+    "@octokit/tsconfig": "^4.0.0",
     "@sinonjs/fake-timers": "^13.0.0",
     "@types/jest": "^29.0.0",
     "@types/lolex": "^5.1.0",