diff --git a/package.json b/package.json
index 9f06fec05..c274fa959 100644
--- a/package.json
+++ b/package.json
@@ -30,15 +30,15 @@
   },
   "scripts": {
     "precommit": "lint-staged",
-    "prepush": "npm run build",
+    "prepush": "yarn run build",
     "test": "jest",
     "test:watch": "jest --watch",
     "lint": "tslint \"source/**/*.ts\"",
     "lint:fix": "tslint \"source/**/*.ts\" --fix",
-    "prepublishOnly": "npm run build && yarn declarations",
-    "build": "shx rm -rf ./distribution && tsc && madge ./distribution --circular",
+    "prepublishOnly": "yarn run build && yarn declarations",
+    "build": "shx rm -rf ./distribution && tsc -p tsconfig.production.json && madge ./distribution --circular",
     "build:watch": "tsc -w",
-    "link": "npm run build && chmod +x distribution/commands/danger.js && npm link",
+    "link": "yarn run build && chmod +x distribution/commands/danger.js && npm link",
     "declarations": "ts-node ./scripts/create-danger-dts.ts",
     "docs:cp_defs":
       "mkdir docs/docs_generate; cp source/danger.d.ts docs/docs_generate; cp node_modules/github/lib/index.d.ts docs/docs_generate/github.d.ts",
diff --git a/source/runner/DangerfileRunner.ts b/source/runner/DangerfileRunner.ts
index 5b563a8e7..447159af0 100644
--- a/source/runner/DangerfileRunner.ts
+++ b/source/runner/DangerfileRunner.ts
@@ -167,7 +167,8 @@ export function cleanDangerfile(contents: string): string {
 
 const typescriptify = (content: string): string => {
   const ts = require("typescript") // tslint:disable-line
-  let result = ts.transpileModule(content, {})
+  const compilerOptions = JSON.parse(fs.readFileSync("tsconfig.json", "utf8"))
+  let result = ts.transpileModule(content, compilerOptions)
   return result.outputText
 }
 
diff --git a/tsconfig.json b/tsconfig.json
index af915551a..b9c93977b 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -14,9 +14,9 @@
     "module": "commonjs",
     "moduleResolution": "node",
     "pretty": true,
-    "target": "es2015",
+    "target": "es5",
     "outDir": "distribution",
-    "lib": ["es5", "es2017"]
+    "lib": ["es2017"]
   },
   "formatCodeOptions": {
     "indentSize": 2,
diff --git a/tsconfig.production.json b/tsconfig.production.json
new file mode 100644
index 000000000..c66c485dc
--- /dev/null
+++ b/tsconfig.production.json
@@ -0,0 +1,12 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": [
+    "dangerfile.ts",
+    "scripts",
+    "node_modules",
+    "source/**/fixtures/*",
+    "source/**/_tests/*",
+    "distribution",
+    "types"
+  ]
+}