diff --git a/package.json b/package.json
index f7a33bb1..f6998324 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
     "@trufflesuite/eth-json-rpc-infura": "^4.0.3-0",
     "@trufflesuite/eth-json-rpc-middleware": "^4.4.2-1",
     "@trufflesuite/eth-sig-util": "^1.4.2",
-    "async": "^2.5.0",
+    "async": "^2.6.4",
     "backoff": "^2.5.0",
     "bluebird": "^3.7.2",
     "clone": "^2.0.0",
diff --git a/yarn.lock b/yarn.lock
index e58ffe21..f2fa3d2e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1223,10 +1223,10 @@ async@^1.4.2:
   resolved "https://registry.yarnpkg.com/async/-/async-1.5.2.tgz#ec6a61ae56480c0c3cb241c95618e20892f9672a"
   integrity sha1-7GphrlZIDAw8skHJVhjiCJL5Zyo=
 
-async@^2.0.1, async@^2.1.2, async@^2.4.0, async@^2.5.0, async@^2.6.1:
-  version "2.6.3"
-  resolved "https://registry.yarnpkg.com/async/-/async-2.6.3.tgz#d72625e2344a3656e3a3ad4fa749fa83299d82ff"
-  integrity sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==
+async@^2.0.1, async@^2.1.2, async@^2.4.0, async@^2.5.0, async@^2.6.1, async@^2.6.4:
+  version "2.6.4"
+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.4.tgz#706b7ff6084664cd7eae713f6f965433b5504221"
+  integrity sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==
   dependencies:
     lodash "^4.17.14"
 
@@ -1888,7 +1888,7 @@ bl@^1.0.0:
     readable-stream "^2.3.5"
     safe-buffer "^5.1.1"
 
-bluebird@^3.5.0:
+bluebird@^3.5.0, bluebird@^3.7.2:
   version "3.7.2"
   resolved "https://registry.yarnpkg.com/bluebird/-/bluebird-3.7.2.tgz#9f229c15be272454ffa973ace0dbee79a1b0c36f"
   integrity sha512-XpNj6GDQzdfW+r2Wnn7xiSAd7TM3jzkxGXBGTtWKuSXv1xUV+azxAm8jdWZN06QTQk+2N2XB9jRDkvbmQmcRtg==
@@ -3138,6 +3138,11 @@ es6-iterator@^2.0.1, es6-iterator@^2.0.3, es6-iterator@~2.0.3:
     es5-ext "^0.10.35"
     es6-symbol "^3.1.1"
 
+es6-promisify@^6.1.1:
+  version "6.1.1"
+  resolved "https://registry.yarnpkg.com/es6-promisify/-/es6-promisify-6.1.1.tgz#46837651b7b06bf6fff893d03f29393668d01621"
+  integrity sha512-HBL8I3mIki5C1Cc9QjKUenHtnG0A5/xA8Q/AllRcfiwl2CZFXGK7ddBiCoRwAix4i2KxcQfjtIVcrVbB3vbmwg==
+
 es6-symbol@^3.1.1, es6-symbol@~3.1.3:
   version "3.1.3"
   resolved "https://registry.yarnpkg.com/es6-symbol/-/es6-symbol-3.1.3.tgz#bad5d3c1bcdac28269f4cb331e431c78ac705d18"