diff --git a/package.json b/package.json
index 3cfd10a..082bd5d 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,7 @@
   "devDependencies": {
     "benchmark": "2.1.4",
     "bitcore-p2p": "^1.1.0",
-    "chai": "^3.5.0",
+    "chai": "^4.2.0",
     "coveralls": "^3.1.0",
     "istanbul": "^0.4.3",
     "jshint": "^2.11.1",
diff --git a/yarn.lock b/yarn.lock
index db9358b..73c6d5e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -152,9 +152,9 @@ assert-plus@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/assert-plus/-/assert-plus-1.0.0.tgz#f12e0f3c5d77b0b1cdd9146942e4e96c1e4dd525"
 
-assertion-error@^1.0.1:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.0.2.tgz#13ca515d86206da0bac66e834dd397d87581094c"
+assertion-error@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.1.0.tgz#e60b6b0e8f301bd97e5375215bda406c85118c0b"
 
 "astracore-lib@https://github.com/AstraCore/astracore-lib.git#master":
   version "0.0.1"
@@ -407,13 +407,16 @@ caseless@~0.12.0:
   version "0.12.0"
   resolved "https://registry.yarnpkg.com/caseless/-/caseless-0.12.0.tgz#1b681c21ff84033c826543090689420d187151dc"
 
-chai@^3.5.0:
-  version "3.5.0"
-  resolved "https://registry.yarnpkg.com/chai/-/chai-3.5.0.tgz#4d02637b067fe958bdbfdd3a40ec56fef7373247"
+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"
-    deep-eql "^0.1.3"
-    type-detect "^1.0.0"
+    assertion-error "^1.1.0"
+    check-error "^1.0.2"
+    deep-eql "^3.0.1"
+    get-func-name "^2.0.0"
+    pathval "^1.1.0"
+    type-detect "^4.0.5"
 
 chalk@^1.0.0:
   version "1.1.3"
@@ -433,6 +436,10 @@ chalk@^2.4.2:
     escape-string-regexp "^1.0.5"
     supports-color "^5.3.0"
 
+check-error@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
+
 chokidar@3.3.1:
   version "3.3.1"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-3.3.1.tgz#c84e5b3d18d9a4d77558fef466b1bf16bbeb3450"
@@ -630,11 +637,11 @@ decamelize@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-1.2.0.tgz#f6534d15148269b20352e7bee26f501f9a191290"
 
-deep-eql@^0.1.3:
-  version "0.1.3"
-  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-0.1.3.tgz#ef558acab8de25206cd713906d74e56930eb69f2"
+deep-eql@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-3.0.1.tgz#dfc9404400ad1c8fe023e7da1df1c147c4b444df"
   dependencies:
-    type-detect "0.1.1"
+    type-detect "^4.0.0"
 
 deep-is@~0.1.3:
   version "0.1.3"
@@ -1126,6 +1133,10 @@ get-caller-file@^2.0.1:
   version "2.0.5"
   resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-2.0.5.tgz#4f94412a82db32f36e3b0b9741f8a97feb031f7e"
 
+get-func-name@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/get-func-name/-/get-func-name-2.0.0.tgz#ead774abee72e20409433a066366023dd6887a41"
+
 getpass@^0.1.1:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/getpass/-/getpass-0.1.7.tgz#5eff8e3e684d569ae4cb2b1282604e8ba62149fa"
@@ -2123,6 +2134,10 @@ path-to-regexp@^1.7.0:
   dependencies:
     isarray "0.0.1"
 
+pathval@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.0.tgz#b942e6d4bde653005ef6b71361def8727d0645e0"
+
 performance-now@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/performance-now/-/performance-now-2.1.0.tgz#6309f4e0e5fa913ec1c69307ae364b4b377c9e7b"
@@ -2627,18 +2642,10 @@ type-check@~0.3.2:
   dependencies:
     prelude-ls "~1.1.2"
 
-type-detect@0.1.1:
-  version "0.1.1"
-  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-0.1.1.tgz#0ba5ec2a885640e470ea4e8505971900dac58822"
-
-type-detect@4.0.8, type-detect@^4.0.8:
+type-detect@4.0.8, type-detect@^4.0.0, type-detect@^4.0.5, type-detect@^4.0.8:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
 
-type-detect@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-1.0.0.tgz#762217cc06db258ec48908a1298e8b95121e8ea2"
-
 type-is@~1.6.17, type-is@~1.6.18:
   version "1.6.18"
   resolved "https://registry.yarnpkg.com/type-is/-/type-is-1.6.18.tgz#4e552cd05df09467dcbc4ef739de89f2cf37c131"