diff --git a/.circleci/config.yml b/.circleci/config.yml
index 1f7f9081..b0efeb7b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -8,11 +8,9 @@ jobs:
       - restore_cache:
           keys:
           - dependencies-{{ checksum "yarn.lock" }}
-          # fallback to using the latest cache if no exact match is found
-          - dependencies-
       - run:
           name: Install
-          command: yarn install
+          command: yarn install --pure-lockfile
       - save_cache:
           paths:
             - node_modules
diff --git a/.nvmrc b/.nvmrc
index c9dc0490..5debbed2 100644
--- a/.nvmrc
+++ b/.nvmrc
@@ -1 +1 @@
-8.4
+lts/carbon
diff --git a/package.json b/package.json
index b1af77b4..2fa983cf 100644
--- a/package.json
+++ b/package.json
@@ -62,7 +62,8 @@
     "unist-util-visit": "^1.1.3"
   },
   "engines": {
-    "node": ">=8.4.0"
+    "node": "^8.4.0",
+    "yarn": "^1.6.0"
   },
   "homepage": "https://reactjs.org/",
   "keywords": [