diff --git a/.travis.yml b/.travis.yml
index 8602dc3..ffd38da 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: node_js
-cache: npm
+cache: yarn
 stages:
   - check
   - test
@@ -14,16 +14,15 @@ os:
   - osx
   - windows
 
-script: npx nyc -s npm run test:node --ts -- --bail
+script: npx nyc -s yarn run test:node --bail
 after_success: npx nyc report --reporter=text-lcov > coverage.lcov && npx codecov
 
 jobs:
   include:
     - stage: check
       script:
-        - npx aegir dep-check
-        - npm run lint --ts
-        - npm run check-types
+        - yarn aegir dep-check
+        - yarn run lint
 
     - stage: test
       name: chrome
diff --git a/package.json b/package.json
index c59916c..ec8079d 100644
--- a/package.json
+++ b/package.json
@@ -16,11 +16,9 @@
   "scripts": {
     "build": "aegir build --ts",
     "lint": "aegir lint --ts",
-    "pretest": "yarn check-types",
     "test": "aegir test --ts",
     "test:node": "aegir test -t node --ts",
     "test:browser": "aegir test -t browser --ts",
-    "check-types": "tsc --noEmit",
     "proto:gen": "pbjs -t static-module -o ./src/proto/payload.js ./src/proto/payload.proto && pbts -o ./src/proto/payload.d.ts ./src/proto/payload.js && yarn run lint --fix"
   },
   "devDependencies": {
diff --git a/tsconfig.json b/tsconfig.json
index cf65253..970ca4c 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -3,6 +3,7 @@
     "target": "ES2018",
     "module": "commonjs",
     "strict": true,
+    "allowJs": true,
     "resolveJsonModule": true,
     "esModuleInterop": true,
     "noImplicitAny": false,
@@ -12,7 +13,8 @@
     ]
   },
   "include": [
-    "**/src/**/*.ts"
+    "**/src/**/*.ts",
+    "**/src/**/*.js"
   ],
   "exclude": [
     "node_modules",