diff --git a/package.json b/package.json
index 9e3e2a7d..2c69f052 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
     "babel-core": "6.26.3",
     "babel-plugin-transform-object-assign": "6.22.0",
     "babel-preset-es2015-rollup": "3.0.0",
-    "chai": "4.1.2",
+    "chai": "4.2.0",
     "cypress": "2.1.0",
     "docsify-cli": "4.2.1",
     "husky": "0.14.3",
diff --git a/yarn.lock b/yarn.lock
index 246f1907..90aa9a6d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -285,7 +285,7 @@ assert-plus@^0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/assert-plus/-/assert-plus-0.2.0.tgz#d74e1b87e7affc0db8aadb7021f3fe48101ab234"
 
-assertion-error@^1.0.1:
+assertion-error@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.1.0.tgz#e60b6b0e8f301bd97e5375215bda406c85118c0b"
 
@@ -871,16 +871,16 @@ caseless@~0.12.0:
   version "0.12.0"
   resolved "https://registry.yarnpkg.com/caseless/-/caseless-0.12.0.tgz#1b681c21ff84033c826543090689420d187151dc"
 
-chai@4.1.2:
-  version "4.1.2"
-  resolved "https://registry.yarnpkg.com/chai/-/chai-4.1.2.tgz#0f64584ba642f0f2ace2806279f4f06ca23ad73c"
+chai@4.2.0:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/chai/-/chai-4.2.0.tgz#760aa72cf20e3795e84b12877ce0e83737aa29e5"
   dependencies:
-    assertion-error "^1.0.1"
-    check-error "^1.0.1"
-    deep-eql "^3.0.0"
+    assertion-error "^1.1.0"
+    check-error "^1.0.2"
+    deep-eql "^3.0.1"
     get-func-name "^2.0.0"
-    pathval "^1.0.0"
-    type-detect "^4.0.0"
+    pathval "^1.1.0"
+    type-detect "^4.0.5"
 
 chalk@1.1.3, chalk@^1.0.0, chalk@^1.1.1, chalk@^1.1.3:
   version "1.1.3"
@@ -912,7 +912,7 @@ chardet@^0.4.0:
   version "0.4.2"
   resolved "https://registry.yarnpkg.com/chardet/-/chardet-0.4.2.tgz#b5473b33dc97c424e5d98dc87d55d4d8a29c8bf2"
 
-check-error@^1.0.1:
+check-error@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
 
@@ -1210,7 +1210,7 @@ deep-assign@^2.0.0:
   dependencies:
     is-obj "^1.0.0"
 
-deep-eql@^3.0.0:
+deep-eql@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-3.0.1.tgz#dfc9404400ad1c8fe023e7da1df1c147c4b444df"
   dependencies:
@@ -2972,7 +2972,7 @@ path-type@^1.0.0:
     pify "^2.0.0"
     pinkie-promise "^2.0.0"
 
-pathval@^1.0.0:
+pathval@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.0.tgz#b942e6d4bde653005ef6b71361def8727d0645e0"
 
@@ -3799,7 +3799,7 @@ type-check@~0.3.2:
   dependencies:
     prelude-ls "~1.1.2"
 
-type-detect@^4.0.0:
+type-detect@^4.0.0, type-detect@^4.0.5:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"