diff --git a/functions/ocr/app/package.json b/functions/ocr/app/package.json
index 41b33ad8c8b..be7eec6a474 100644
--- a/functions/ocr/app/package.json
+++ b/functions/ocr/app/package.json
@@ -28,7 +28,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "3.2.1"
+    "sinon": "3.3.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/language/slackbot/package.json b/language/slackbot/package.json
index cf978b6bd9e..8f60af3fc4a 100644
--- a/language/slackbot/package.json
+++ b/language/slackbot/package.json
@@ -29,6 +29,6 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "3.2.0"
+    "sinon": "3.3.0"
   }
 }