diff --git a/packages/lit-override/package.json b/packages/lit-override/package.json
index db51c939..99cc24bd 100644
--- a/packages/lit-override/package.json
+++ b/packages/lit-override/package.json
@@ -68,7 +68,7 @@
     "lit-html": "3.3.0",
     "playwright": "1.52.0",
     "rimraf": "5.0.10",
-    "sinon": "17.0.1",
+    "sinon": "18.0.1",
     "tsconfig-config": "workspace:*",
     "tslib": "2.8.1",
     "tsup": "8.4.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 15acadb9..67a5a4cf 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -417,8 +417,8 @@ importers:
         specifier: 5.0.10
         version: 5.0.10
       sinon:
-        specifier: 17.0.1
-        version: 17.0.1
+        specifier: 18.0.1
+        version: 18.0.1
       tsconfig-config:
         specifier: workspace:*
         version: link:../../configs/tsconfig-config
@@ -6151,6 +6151,12 @@ packages:
       '@sinonjs/commons': 3.0.1
     dev: true
 
+  /@sinonjs/fake-timers@13.0.5:
+    resolution: {integrity: sha512-36/hTbH2uaWuGVERyC6da9YwGWnzUZXuPro/F2LfsdOsLnCojz/iSH8MxUt/FD2S5XBSVPhmArFUXcpCQ2Hkiw==}
+    dependencies:
+      '@sinonjs/commons': 3.0.1
+    dev: true
+
   /@sinonjs/samsam@8.0.0:
     resolution: {integrity: sha512-Bp8KUVlLp8ibJZrnvq2foVhP0IVX2CIprMJPK0vqGqgrDa0OHVKeZyBykqskkrdxV6yKBPmGasO8LVjAKR3Gew==}
     dependencies:
@@ -6159,8 +6165,8 @@ packages:
       type-detect: 4.0.8
     dev: true
 
-  /@sinonjs/text-encoding@0.7.2:
-    resolution: {integrity: sha512-sXXKG+uL9IrKqViTtao2Ws6dy0znu9sOaP1di/jKGW1M6VssO8vlpXCQcpZ+jisQ1tTFAC5Jo/EOzFbggBagFQ==}
+  /@sinonjs/text-encoding@0.7.3:
+    resolution: {integrity: sha512-DE427ROAphMQzU4ENbliGYrBSYPXF+TtLg9S8vzeA+OF4ZKzoDdzfL8sxuMUGS/lgRhM6j1URSk9ghf7Xo1tyA==}
     dev: true
 
   /@snyk/github-codeowners@1.1.0:
@@ -14874,6 +14880,7 @@ packages:
 
   /lodash.get@4.4.2:
     resolution: {integrity: sha512-z+Uw/vLuy6gQe8cfaFWD7p0wVv8fJl3mbzXh33RS+0oW2wvUqiRXiQ69gLWSLpgB5/6sU+r6BlQR0MBILadqTQ==}
+    deprecated: This package is deprecated. Use the optional chaining (?.) operator instead.
     dev: true
 
   /lodash.isequal@4.5.0:
@@ -16350,14 +16357,14 @@ packages:
       type-fest: 2.19.0
     dev: false
 
-  /nise@5.1.9:
-    resolution: {integrity: sha512-qOnoujW4SV6e40dYxJOb3uvuoPHtmLzIk4TFo+j0jPJoC+5Z9xja5qH5JZobEPsa8+YYphMrOSwnrshEhG2qww==}
+  /nise@6.1.1:
+    resolution: {integrity: sha512-aMSAzLVY7LyeM60gvBS423nBmIPP+Wy7St7hsb+8/fc1HmeoHJfLO8CKse4u3BtOZvQLJghYPI2i/1WZrEj5/g==}
     dependencies:
       '@sinonjs/commons': 3.0.1
-      '@sinonjs/fake-timers': 11.2.2
-      '@sinonjs/text-encoding': 0.7.2
+      '@sinonjs/fake-timers': 13.0.5
+      '@sinonjs/text-encoding': 0.7.3
       just-extend: 6.2.0
-      path-to-regexp: 6.2.2
+      path-to-regexp: 8.2.0
     dev: true
 
   /node-addon-api@3.2.1:
@@ -17301,8 +17308,9 @@ packages:
     resolution: {integrity: sha512-gu9bD6Ta5bwGrrU8muHzVOBFFREpp2iRkVfhBJahwJ6p6Xw20SjT0MxLnwkjOibQmGSYhiUnf2FLe7k+jcFmGQ==}
     dev: true
 
-  /path-to-regexp@6.2.2:
-    resolution: {integrity: sha512-GQX3SSMokngb36+whdpRXE+3f9V8UzyAorlYvOGx87ufGHehNTn5lCxrKtLyZ4Yl/wEKnNnr98ZzOwwDZV5ogw==}
+  /path-to-regexp@8.2.0:
+    resolution: {integrity: sha512-TdrF7fW9Rphjq4RjrW0Kp2AW0Ahwu9sRGTkS6bvDi0SCwZlEZYmcfDbEsTz8RVk0EHIS/Vd1bv3JhG+1xZuAyQ==}
+    engines: {node: '>=16'}
     dev: true
 
   /path-type@4.0.0:
@@ -18775,14 +18783,14 @@ packages:
       - supports-color
     dev: false
 
-  /sinon@17.0.1:
-    resolution: {integrity: sha512-wmwE19Lie0MLT+ZYNpDymasPHUKTaZHUH/pKEubRXIzySv9Atnlw+BUMGCzWgV7b7wO+Hw6f1TEOr0IUnmU8/g==}
+  /sinon@18.0.1:
+    resolution: {integrity: sha512-a2N2TDY1uGviajJ6r4D1CyRAkzE9NNVlYOV1wX5xQDuAk0ONgzgRl0EjCQuRCPxOwp13ghsMwt9Gdldujs39qw==}
     dependencies:
       '@sinonjs/commons': 3.0.1
       '@sinonjs/fake-timers': 11.2.2
       '@sinonjs/samsam': 8.0.0
       diff: 5.2.0
-      nise: 5.1.9
+      nise: 6.1.1
       supports-color: 7.2.0
     dev: true