diff --git a/circle.yml b/circle.yml
index b7b916c3..9e0828f2 100644
--- a/circle.yml
+++ b/circle.yml
@@ -2,15 +2,25 @@
 
 machine:
   node:
-    version: 6.11.4
+    version: 6.11.5
   environment:
-    PATH: "${PATH}:${HOME}/${CIRCLE_PROJECT_REPONAME}/node_modules/.bin"
+    YARN_VERSION: 1.2.1
+    PATH: "${PATH}:${HOME}/.yarn/bin:${HOME}/${CIRCLE_PROJECT_REPONAME}/node_modules/.bin"
 
 dependencies:
+  pre:
+    - |
+      if [[ ! -e ~/.yarn/bin/yarn || $(yarn --version) != "${YARN_VERSION}" ]]; then
+        echo "Downloading and installing Yarn"
+        curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version $YARN_VERSION
+      else
+        echo "The correct version of Yarn is already installed"
+      fi
   override:
     - yarn
   cache_directories:
     - ~/.cache/yarn
+    - ~/.yarn
 
 test:
   pre:
diff --git a/package.json b/package.json
index 6f1c133d..d80a8de7 100644
--- a/package.json
+++ b/package.json
@@ -72,7 +72,7 @@
     "trailingComma": "es5"
   },
   "engines": {
-    "node": "6.11.4",
+    "node": "6.11.5",
     "yarn": "^1.2.1"
   }
 }