diff --git a/endpoints/getting-started/package.json b/endpoints/getting-started/package.json
index b250f0b9eb9..4eb0b037caf 100644
--- a/endpoints/getting-started/package.json
+++ b/endpoints/getting-started/package.json
@@ -25,7 +25,7 @@
     "@google-cloud/nodejs-repo-tools": "^2.3.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.2",
+    "sinon": "4.5.0",
     "supertest": "3.3.0"
   }
 }
diff --git a/functions/background/package.json b/functions/background/package.json
index 535808ab243..ef428378f52 100644
--- a/functions/background/package.json
+++ b/functions/background/package.json
@@ -25,7 +25,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/composer-storage-trigger/package.json b/functions/composer-storage-trigger/package.json
index 07accc4300d..c7c1c3ea027 100644
--- a/functions/composer-storage-trigger/package.json
+++ b/functions/composer-storage-trigger/package.json
@@ -20,7 +20,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "scripts": {
     "lint": "semistandard '**/*.js'",
diff --git a/functions/datastore/package.json b/functions/datastore/package.json
index 7ef57607e27..0373833a7e0 100644
--- a/functions/datastore/package.json
+++ b/functions/datastore/package.json
@@ -28,7 +28,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/env_vars/package.json b/functions/env_vars/package.json
index 8a94623b935..26f31f78fb5 100644
--- a/functions/env_vars/package.json
+++ b/functions/env_vars/package.json
@@ -21,7 +21,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/firebase/package.json b/functions/firebase/package.json
index 0bb349f02cb..319044e5a7c 100644
--- a/functions/firebase/package.json
+++ b/functions/firebase/package.json
@@ -20,7 +20,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.8",
+    "sinon": "4.5.0",
     "supertest": "^3.0.0",
     "uuid": "^3.1.0"
   },
diff --git a/functions/gcs/package.json b/functions/gcs/package.json
index f3fb8adc052..0e894f19212 100644
--- a/functions/gcs/package.json
+++ b/functions/gcs/package.json
@@ -25,7 +25,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/helloworld/package.json b/functions/helloworld/package.json
index 7c31835a024..c0ee8f24bb1 100644
--- a/functions/helloworld/package.json
+++ b/functions/helloworld/package.json
@@ -32,7 +32,7 @@
     "express": "^4.16.3",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.8",
+    "sinon": "4.5.0",
     "supertest": "^3.0.0",
     "uuid": "^3.1.0",
     "yargs": "^11.0.0"
diff --git a/functions/http/package.json b/functions/http/package.json
index ddeb9c82f30..f67bc20bf44 100644
--- a/functions/http/package.json
+++ b/functions/http/package.json
@@ -21,7 +21,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "dependencies": {
     "@google-cloud/storage": "1.7.0",
diff --git a/functions/imagemagick/package.json b/functions/imagemagick/package.json
index be636d31edb..cc95b4dad64 100644
--- a/functions/imagemagick/package.json
+++ b/functions/imagemagick/package.json
@@ -26,7 +26,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/log/package.json b/functions/log/package.json
index bc24decfd77..9a7054074e0 100644
--- a/functions/log/package.json
+++ b/functions/log/package.json
@@ -25,7 +25,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/pubsub/package.json b/functions/pubsub/package.json
index 182210fd5ce..d3270fa9a25 100644
--- a/functions/pubsub/package.json
+++ b/functions/pubsub/package.json
@@ -25,7 +25,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/sendgrid/package.json b/functions/sendgrid/package.json
index b31ff5d8543..0712249d7eb 100644
--- a/functions/sendgrid/package.json
+++ b/functions/sendgrid/package.json
@@ -28,7 +28,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.0.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/slack/package.json b/functions/slack/package.json
index 1163635ec3c..49f1238e7fc 100644
--- a/functions/slack/package.json
+++ b/functions/slack/package.json
@@ -24,7 +24,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.0.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/spanner/package.json b/functions/spanner/package.json
index a162feb7961..f7fd43f7201 100644
--- a/functions/spanner/package.json
+++ b/functions/spanner/package.json
@@ -24,7 +24,7 @@
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/sql/package.json b/functions/sql/package.json
index 3513f795019..a6eaa166a11 100644
--- a/functions/sql/package.json
+++ b/functions/sql/package.json
@@ -30,7 +30,7 @@
     "ava": "0.25.0",
     "proxyquire": "^2.1.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/uuid/package.json b/functions/uuid/package.json
index 1f707a31e73..8e714e3a895 100644
--- a/functions/uuid/package.json
+++ b/functions/uuid/package.json
@@ -23,7 +23,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "semistandard": "^12.0.1",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/storage-transfer/package.json b/storage-transfer/package.json
index 92b928c0ba8..ac28e7cd101 100644
--- a/storage-transfer/package.json
+++ b/storage-transfer/package.json
@@ -27,7 +27,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.8",
+    "sinon": "4.5.0",
     "uuid": "3.3.2"
   },
   "cloud-repo-tools": {