diff --git a/package-lock.json b/package-lock.json
index c20474d..8453562 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17,7 +17,7 @@
         "veriwhy-check": "dist/src/cli.js"
       },
       "devDependencies": {
-        "@types/node": "^24.10.0",
+        "@types/node": "^26.5.0",
         "markdownlint-cli2": "^0.23.2",
         "prettier": "^3.9.6",
         "typescript": "^6.0.0"
@@ -102,13 +102,13 @@
       "license": "MIT"
     },
     "node_modules/@types/node": {
-      "version": "24.13.3",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-24.13.3.tgz",
-      "integrity": "sha512-Dh8vAsV36ig5wa9OX4pXvMc9D3Veibfw2wix0CUwYODLD8nkj9UsLjASr49nPg+2eKzxhBV+v7L8pXvT4e639Q==",
+      "version": "26.5.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-26.5.0.tgz",
+      "integrity": "sha512-dVSGpriSoCgz8WnDNTuSSuSv1PC/ALXihO4ulRZt7Md8k9mlbdin3lGOcDE8SnWOgf513ByWlXd7BK4azmyg/A==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "undici-types": "~7.18.0"
+        "undici-types": "~8.9.0"
       }
     },
     "node_modules/@types/unist": {
@@ -1462,9 +1462,9 @@
       "license": "MIT"
     },
     "node_modules/undici-types": {
-      "version": "7.18.2",
-      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.18.2.tgz",
-      "integrity": "sha512-AsuCzffGHJybSaRrmr5eHr81mwJU3kjw6M+uprWvCXiNeN9SOGwQ3Jn8jb8m3Z6izVgknn1R0FTCEAP2QrLY/w==",
+      "version": "8.9.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-8.9.0.tgz",
+      "integrity": "sha512-KTDyRTYX8sWmKXAikPHHSyc63CRPETMctyjKFupcC6OBLXT3xsN0e9aF7m+mIXutFWpUXuedtowG7iLOzp0kQg==",
       "dev": true,
       "license": "MIT"
     },
diff --git a/package.json b/package.json
index bcd3eb0..83eeca6 100644
--- a/package.json
+++ b/package.json
@@ -34,7 +34,7 @@
     "yaml": "^2.9.0"
   },
   "devDependencies": {
-    "@types/node": "^24.10.0",
+    "@types/node": "^26.5.0",
     "markdownlint-cli2": "^0.23.2",
     "prettier": "^3.9.6",
     "typescript": "^6.0.0"