diff --git a/.circleci/config.yml b/.circleci/config.yml
index edc0625..11b6c5e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -2,7 +2,7 @@ version: 2
 jobs:
   test:
     docker:
-      - image: circleci/node:4-browsers
+      - image: circleci/node:12-browsers
     steps:
       - checkout
       - restore_cache:
@@ -29,7 +29,7 @@ jobs:
             - node_modules
   publish:
     docker:
-      - image: circleci/node:4-browsers
+      - image: circleci/node:12-browsers
     steps:
       - checkout
       - run:
diff --git a/package.json b/package.json
index 3cbcb26..382c57a 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
     "component-emitter": "^1.2.0",
     "debug": "^2.2.0",
     "domify": "^1.4.0",
-    "extend": "3.0.1",
+    "extend": "^3.0.2",
     "is": "^3.1.0",
     "load-iframe": "^1.0.0",
     "next-tick": "^0.2.2",
diff --git a/yarn.lock b/yarn.lock
index d107bc3..7513757 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1572,10 +1572,15 @@ expand-range@^1.8.1:
   dependencies:
     fill-range "^2.1.0"
 
-extend@3, extend@3.0.1, extend@^3.0.0, extend@~3.0.0, extend@~3.0.1:
+extend@3, extend@^3.0.0, extend@~3.0.0, extend@~3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/extend/-/extend-3.0.1.tgz#a755ea7bc1adfcc5a31ce7e762dbaadc5e636444"
 
+extend@^3.0.2:
+  version "3.0.2"
+  resolved "https://registry.yarnpkg.com/extend/-/extend-3.0.2.tgz#f8b1136b4071fbd8eb140aff858b1019ec2915fa"
+  integrity sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g==
+
 extglob@^0.3.1:
   version "0.3.2"
   resolved "https://registry.yarnpkg.com/extglob/-/extglob-0.3.2.tgz#2e18ff3d2f49ab2765cec9023f011daa8d8349a1"