diff --git a/package.json b/package.json
index 5c93bf5bbfa62edf39360e5f34a34885027e3cef..7c5a82c56d2dc5dadb6054731a08e1ebd017274d 100644
--- a/package.json
+++ b/package.json
@@ -120,7 +120,7 @@
     "validator": "10.8.0",
     "vso-node-api": "6.5.0",
     "www-authenticate": "0.6.2",
-    "yarn": "1.10.1"
+    "yarn": "1.9.4"
   },
   "devDependencies": {
     "babel-plugin-transform-object-rest-spread": "6.26.0",
diff --git a/yarn.lock b/yarn.lock
index df26f85b7ee6f3bae14a511af97bf71d0429eed1..f85bd8f526a11866e5e381cff33233772a07a3f8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9206,7 +9206,7 @@ yargs@~3.10.0:
     decamelize "^1.0.0"
     window-size "0.1.0"
 
-yarn@1.10.1:
-  version "1.10.1"
-  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.10.1.tgz#b792ba28f050ae94cd7e719dbca80639d70da76f"
-  integrity sha512-EH0H1fyfFxkE4UpG4b+VCaVY4I488I2EyQNmGjGGKmvsSIb0G3b+1IcfGYPI2gqa1du43g4ZA3jH8fXlq6oVxg==
+yarn@1.9.4:
+  version "1.9.4"
+  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.9.4.tgz#3b82d8446b652775723900b470d966861976924b"
+  integrity sha1-O4LYRGtlJ3VyOQC0cNlmhhl2kks=