diff --git a/package.json b/package.json
index cfa53f61..6e4f9529 100644
--- a/package.json
+++ b/package.json
@@ -13,13 +13,13 @@
     "heroku-postbuild": "npm run build"
   },
   "dependencies": {
-    "js-yaml": "3.14.1",
+    "js-yaml": "4.0.0",
     "probot": "9.15.1"
   },
   "devDependencies": {
     "@types/bunyan": "1.8.6",
     "@types/jest": "26.0.20",
-    "@types/js-yaml": "3.12.6",
+    "@types/js-yaml": "4.0.0",
     "@types/node": "10.17.54",
     "jest": "26.6.3",
     "nodemon": "2.0.7",
diff --git a/yarn.lock b/yarn.lock
index a43cc729..b45b0900 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -764,10 +764,10 @@
     jest-diff "^26.0.0"
     pretty-format "^26.0.0"
 
-"@types/js-yaml@3.12.6":
-  version "3.12.6"
-  resolved "https://registry.yarnpkg.com/@types/js-yaml/-/js-yaml-3.12.6.tgz#7f10c926aa41e189a2755c4c7fcf8e4573bd7ac1"
-  integrity sha512-cK4XqrLvP17X6c0C8n4iTbT59EixqyXL3Fk8/Rsk4dF3oX4dg70gYUXrXVUUHpnsGMPNlTQMqf+TVmNPX6FmSQ==
+"@types/js-yaml@4.0.0":
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/@types/js-yaml/-/js-yaml-4.0.0.tgz#d1a11688112091f2c711674df3a65ea2f47b5dfb"
+  integrity sha512-4vlpCM5KPCL5CfGmTbpjwVKbISRYhduEJvvUWsH5EB7QInhEj94XPZ3ts/9FPiLZFqYO0xoW4ZL8z2AabTGgJA==
 
 "@types/mime@^1":
   version "1.3.2"
@@ -951,6 +951,11 @@ argparse@^1.0.7:
   dependencies:
     sprintf-js "~1.0.2"
 
+argparse@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/argparse/-/argparse-2.0.1.tgz#246f50f3ca78a3240f6c997e8a9bd1eac49e4b38"
+  integrity sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==
+
 arr-diff@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/arr-diff/-/arr-diff-4.0.0.tgz#d6461074febfec71e7e15235761a329a5dc7c520"
@@ -3155,7 +3160,14 @@ js-tokens@^4.0.0:
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-4.0.0.tgz#19203fb59991df98e3a287050d4647cdeaf32499"
   integrity sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ==
 
-js-yaml@3.14.1, js-yaml@^3.13.1:
+js-yaml@4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-4.0.0.tgz#f426bc0ff4b4051926cd588c71113183409a121f"
+  integrity sha512-pqon0s+4ScYUvX30wxQi3PogGFAlUyH0awepWvwkj4jD4v+ova3RiYw8bmA6x2rDrEaj8i/oWKoRxpVNW+Re8Q==
+  dependencies:
+    argparse "^2.0.1"
+
+js-yaml@^3.13.1:
   version "3.14.1"
   resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.14.1.tgz#dae812fdb3825fa306609a8717383c50c36a0537"
   integrity sha512-okMH7OXXJ7YrN9Ok3/SXrnu4iX9yOk+25nqX4imS2npuvTYDmo/QEZoqwZkYaIDk3jVvBOTOIEgEhaLOynBS9g==