diff --git a/package.json b/package.json
index b40fe2c..6a15638 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,7 @@
     "nyc": "^12.0.1",
     "power-assert": "^1.4.4",
     "shx": "^0.3.0",
-    "sinon": "^6.0.0",
+    "sinon": "^9.0.0",
     "ts-loader": "^3.2.0",
     "tslint": "^5.9.1",
     "typescript": "^2.7.2",