diff --git a/decision-service/package.json b/decision-service/package.json
index f205d0e..e0d7c45 100644
--- a/decision-service/package.json
+++ b/decision-service/package.json
@@ -33,7 +33,7 @@
   "devDependencies": {
     "babel-core": "6.26.3",
     "babel-eslint": "9.0.0",
-    "babel-polyfill": "^6.26.0",
+    "babel-polyfill": "6.26.0",
     "babel-preset-latest": "6.24.1",
     "babel-register": "6.26.0",
     "chai": "4.2.0",
diff --git a/decision-service/yarn.lock b/decision-service/yarn.lock
index b3e0df2..98da035 100644
--- a/decision-service/yarn.lock
+++ b/decision-service/yarn.lock
@@ -345,7 +345,7 @@ babel-code-frame@^6.26.0:
     esutils "^2.0.2"
     js-tokens "^3.0.2"
 
-babel-core@^6.26.0, babel-core@^6.26.3:
+babel-core@6.26.3, babel-core@^6.26.0:
   version "6.26.3"
   resolved "https://registry.yarnpkg.com/babel-core/-/babel-core-6.26.3.tgz#b2e2f09e342d0f0c88e2f02e067794125e75c207"
   integrity sha512-6jyFLuDmeidKmUEb3NM+/yawG0M2bDZ9Z1qbZP59cyHLz8kYGKYwpJP0UwUKKUiTRNvxfLesJnTedqczP7cTDA==
@@ -761,7 +761,7 @@ babel-plugin-transform-strict-mode@^6.24.1:
     babel-runtime "^6.22.0"
     babel-types "^6.24.1"
 
-babel-polyfill@^6.26.0:
+babel-polyfill@6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-polyfill/-/babel-polyfill-6.26.0.tgz#379937abc67d7895970adc621f284cd966cf2153"
   integrity sha1-N5k3q8Z9eJWXCtxiHyhM2WbPIVM=
@@ -815,7 +815,7 @@ babel-preset-es2017@^6.24.1:
     babel-plugin-syntax-trailing-function-commas "^6.22.0"
     babel-plugin-transform-async-to-generator "^6.24.1"
 
-babel-preset-latest@^6.24.1:
+babel-preset-latest@6.24.1:
   version "6.24.1"
   resolved "https://registry.yarnpkg.com/babel-preset-latest/-/babel-preset-latest-6.24.1.tgz#677de069154a7485c2d25c577c02f624b85b85e8"
   integrity sha1-Z33gaRVKdIXC0lxXfAL2JLhbheg=
@@ -824,7 +824,7 @@ babel-preset-latest@^6.24.1:
     babel-preset-es2016 "^6.24.1"
     babel-preset-es2017 "^6.24.1"
 
-babel-register@^6.26.0:
+babel-register@6.26.0, babel-register@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-register/-/babel-register-6.26.0.tgz#6ed021173e2fcb486d7acb45c6009a856f647071"
   integrity sha1-btAhFz4vy0htestFxgCahW9kcHE=
@@ -1081,7 +1081,7 @@ caseless@~0.12.0:
   resolved "https://registry.yarnpkg.com/caseless/-/caseless-0.12.0.tgz#1b681c21ff84033c826543090689420d187151dc"
   integrity sha1-G2gcIf+EAzyCZUMJBolCDRhxUdw=
 
-chai-http@^4.2.1:
+chai-http@4.2.1:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/chai-http/-/chai-http-4.2.1.tgz#d4db6ae491e46b7d5029b2c103b6af45cd5ae290"
   integrity sha512-S2Ezy5uSVuOYleeXppfUKtTU/xbHCZyKkwjheNJ/76SGFTUPDpDkkpVdPNgC3sAO1Ap5J5LJ+/rXdLG8EGhCDA==
@@ -1094,7 +1094,7 @@ chai-http@^4.2.1:
     qs "^6.5.1"
     superagent "^3.7.0"
 
-chai@^4.2.0:
+chai@4.2.0:
   version "4.2.0"
   resolved "https://registry.yarnpkg.com/chai/-/chai-4.2.0.tgz#760aa72cf20e3795e84b12877ce0e83737aa29e5"
   integrity sha512-XQU3bhBukrOsQCuwZndwGcCVQHyZi53fQ6Ys1Fym7E4olpIqqZZhhoFJoaKVvV17lWQoXYwgWN2nF5crA8J2jw==
@@ -3239,7 +3239,7 @@ mkdirp@0.5.1, mkdirp@^0.5.0, mkdirp@^0.5.1:
   dependencies:
     minimist "0.0.8"
 
-mocha@^6.0.2:
+mocha@6.0.2:
   version "6.0.2"
   resolved "https://registry.yarnpkg.com/mocha/-/mocha-6.0.2.tgz#cdc1a6fdf66472c079b5605bac59d29807702d2c"
   integrity sha512-RtTJsmmToGyeTznSOMoM6TPEk1A84FQaHIciKrRqARZx+B5ccJ5tXlmJzEKGBxZdqk9UjpRsesZTUkZmR5YnuQ==