diff --git a/package-lock.json b/package-lock.json
index 01c8ce9..7dca920 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21,7 +21,7 @@
         "eslint": "^9.0.0",
         "mocha": "^10.8.2",
         "ovsx": "^0.9.0",
-        "sinon": "^19.0.2",
+        "sinon": "^21.0.0",
         "typescript": "^5.6.3"
       },
       "engines": {
@@ -1289,13 +1289,6 @@
         "node": ">=4"
       }
     },
-    "node_modules/@sinonjs/text-encoding": {
-      "version": "0.7.3",
-      "resolved": "https://registry.npmjs.org/@sinonjs/text-encoding/-/text-encoding-0.7.3.tgz",
-      "integrity": "sha512-DE427ROAphMQzU4ENbliGYrBSYPXF+TtLg9S8vzeA+OF4ZKzoDdzfL8sxuMUGS/lgRhM6j1URSk9ghf7Xo1tyA==",
-      "dev": true,
-      "license": "(Unlicense OR Apache-2.0)"
-    },
     "node_modules/@textlint/ast-node-types": {
       "version": "15.2.2",
       "resolved": "https://registry.npmjs.org/@textlint/ast-node-types/-/ast-node-types-15.2.2.tgz",
@@ -4607,13 +4600,6 @@
         "safe-buffer": "~5.1.0"
       }
     },
-    "node_modules/just-extend": {
-      "version": "6.2.0",
-      "resolved": "https://registry.npmjs.org/just-extend/-/just-extend-6.2.0.tgz",
-      "integrity": "sha512-cYofQu2Xpom82S6qD778jBDpwvvy39s1l/hrYij2u9AMdQcGRpaBu6kY4mVhuno5kJVi1DAz4aiphA2WI1/OAw==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/jwa": {
       "version": "1.4.2",
       "resolved": "https://registry.npmjs.org/jwa/-/jwa-1.4.2.tgz",
@@ -5216,20 +5202,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/nise": {
-      "version": "6.1.1",
-      "resolved": "https://registry.npmjs.org/nise/-/nise-6.1.1.tgz",
-      "integrity": "sha512-aMSAzLVY7LyeM60gvBS423nBmIPP+Wy7St7hsb+8/fc1HmeoHJfLO8CKse4u3BtOZvQLJghYPI2i/1WZrEj5/g==",
-      "dev": true,
-      "license": "BSD-3-Clause",
-      "dependencies": {
-        "@sinonjs/commons": "^3.0.1",
-        "@sinonjs/fake-timers": "^13.0.1",
-        "@sinonjs/text-encoding": "^0.7.3",
-        "just-extend": "^6.2.0",
-        "path-to-regexp": "^8.1.0"
-      }
-    },
     "node_modules/node-abi": {
       "version": "3.77.0",
       "resolved": "https://registry.npmjs.org/node-abi/-/node-abi-3.77.0.tgz",
@@ -5740,17 +5712,6 @@
         "url": "https://github.com/sponsors/isaacs"
       }
     },
-    "node_modules/path-to-regexp": {
-      "version": "8.3.0",
-      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-8.3.0.tgz",
-      "integrity": "sha512-7jdwVIRtsP8MYpdXSwOS0YdD0Du+qOoF/AEPIt88PcCFrZCzx41oxku1jD88hZBwbNUIEfpqvuhjFaMAqMTWnA==",
-      "dev": true,
-      "license": "MIT",
-      "funding": {
-        "type": "opencollective",
-        "url": "https://opencollective.com/express"
-      }
-    },
     "node_modules/path-type": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/path-type/-/path-type-6.0.0.tgz",
@@ -6385,9 +6346,9 @@
       }
     },
     "node_modules/sinon": {
-      "version": "19.0.5",
-      "resolved": "https://registry.npmjs.org/sinon/-/sinon-19.0.5.tgz",
-      "integrity": "sha512-r15s9/s+ub/d4bxNXqIUmwp6imVSdTorIRaxoecYjqTVLZ8RuoXr/4EDGwIBo6Waxn7f2gnURX9zuhAfCwaF6Q==",
+      "version": "21.0.0",
+      "resolved": "https://registry.npmjs.org/sinon/-/sinon-21.0.0.tgz",
+      "integrity": "sha512-TOgRcwFPbfGtpqvZw+hyqJDvqfapr1qUlOizROIk4bBLjlsjlB00Pg6wMFXNtJRpu+eCZuVOaLatG7M8105kAw==",
       "dev": true,
       "license": "BSD-3-Clause",
       "dependencies": {
@@ -6395,7 +6356,6 @@
         "@sinonjs/fake-timers": "^13.0.5",
         "@sinonjs/samsam": "^8.0.1",
         "diff": "^7.0.0",
-        "nise": "^6.1.1",
         "supports-color": "^7.2.0"
       },
       "funding": {
diff --git a/package.json b/package.json
index eb60a0d..bcf7f76 100644
--- a/package.json
+++ b/package.json
@@ -135,7 +135,7 @@
     "eslint": "^9.0.0",
     "mocha": "^10.8.2",
     "ovsx": "^0.9.0",
-    "sinon": "^19.0.2",
+    "sinon": "^21.0.0",
     "typescript": "^5.6.3"
   }
 }