diff --git a/endpoints/getting-started/package.json b/endpoints/getting-started/package.json
index 0929b724bf..196b4e176d 100644
--- a/endpoints/getting-started/package.json
+++ b/endpoints/getting-started/package.json
@@ -25,7 +25,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "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 4ae1d74fa8..e6e66ed0f0 100644
--- a/functions/background/package.json
+++ b/functions/background/package.json
@@ -22,7 +22,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "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 b46eb80143..e8b230ee48 100644
--- a/functions/composer-storage-trigger/package.json
+++ b/functions/composer-storage-trigger/package.json
@@ -19,7 +19,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "scripts": {
     "test": "ava -T 20s --verbose test/*.test.js"
diff --git a/functions/datastore/package.json b/functions/datastore/package.json
index c3d2ab0bc4..a5bcd36b8d 100644
--- a/functions/datastore/package.json
+++ b/functions/datastore/package.json
@@ -25,7 +25,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.2",
+    "sinon": "4.5.0",
     "uuid": "^3.3.2"
   },
   "cloud-repo-tools": {
diff --git a/functions/env_vars/package.json b/functions/env_vars/package.json
index 9e93df7fc1..44f8cb13a3 100644
--- a/functions/env_vars/package.json
+++ b/functions/env_vars/package.json
@@ -18,7 +18,7 @@
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
-    "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 d49e79f188..25bd3818b6 100644
--- a/functions/firebase/package.json
+++ b/functions/firebase/package.json
@@ -18,7 +18,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.8",
+    "sinon": "4.5.0",
     "supertest": "^3.0.0",
     "uuid": "^3.1.0"
   },
diff --git a/functions/helloworld/package.json b/functions/helloworld/package.json
index b8060e59ee..007731feca 100644
--- a/functions/helloworld/package.json
+++ b/functions/helloworld/package.json
@@ -29,7 +29,7 @@
     "ava": "0.25.0",
     "express": "^4.16.3",
     "proxyquire": "2.1.0",
-    "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 a6275b3b89..ca43ade59f 100644
--- a/functions/http/package.json
+++ b/functions/http/package.json
@@ -18,7 +18,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.2",
+    "sinon": "4.5.0",
     "uuid": "^3.3.2"
   },
   "dependencies": {
diff --git a/functions/imagemagick/package.json b/functions/imagemagick/package.json
index 442f38482f..6cbe992e3a 100644
--- a/functions/imagemagick/package.json
+++ b/functions/imagemagick/package.json
@@ -23,7 +23,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "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 9f946c2173..d587f213ea 100644
--- a/functions/log/package.json
+++ b/functions/log/package.json
@@ -22,7 +22,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "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 d266098589..ea8229f5dc 100644
--- a/functions/pubsub/package.json
+++ b/functions/pubsub/package.json
@@ -22,7 +22,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/slack/package.json b/functions/slack/package.json
index dd0030ecb9..8767f29ff4 100644
--- a/functions/slack/package.json
+++ b/functions/slack/package.json
@@ -21,7 +21,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "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 f5da0b18bb..2eecc2ae92 100644
--- a/functions/spanner/package.json
+++ b/functions/spanner/package.json
@@ -21,7 +21,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "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 d8ae5a4ff6..6b766c2f7e 100644
--- a/functions/sql/package.json
+++ b/functions/sql/package.json
@@ -27,7 +27,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "^2.1.0",
-    "sinon": "4.4.2"
+    "sinon": "4.5.0"
   },
   "cloud-repo-tools": {
     "requiresKeyFile": true,
diff --git a/functions/uuid/package.json b/functions/uuid/package.json
index c822288687..96e35243e3 100644
--- a/functions/uuid/package.json
+++ b/functions/uuid/package.json
@@ -20,7 +20,7 @@
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
-    "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 dd2b4f5d47..b940bad1d0 100644
--- a/storage-transfer/package.json
+++ b/storage-transfer/package.json
@@ -25,7 +25,7 @@
     "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "ava": "0.25.0",
     "proxyquire": "2.1.0",
-    "sinon": "4.4.8",
+    "sinon": "4.5.0",
     "@google-cloud/storage": "1.7.0",
     "uuid": "3.3.2"
   },