diff --git a/.circleci/config.yml b/.circleci/config.yml
index 53abbc89..af2574b7 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -8,6 +8,7 @@ jobs:
       - checkout
       - run: yarn install
       - run: yarn bootstrap
+      - run: yarn lint
       - run: yarn test
   publish-stable:
     docker:
diff --git a/package.json b/package.json
index af94fb5f..e86cceb1 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,8 @@
     "pretest": "npm run lint",
     "test": "npm run testall || npm run testall",
     "coveralls": "cat ./test/coverage/lcov.info | coveralls",
-    "lint": "standard && standard --parser typescript-eslint-parser --plugin typescript packages/**/*.ts",
+    "lint": "lerna run typescript && standard && standard --parser typescript-eslint-parser --plugin typescript packages/**/*.ts",
+    "typescript": "lerna run typescript",
     "prepublish": "lerna run prepublish",
     "publish-canary": "lerna version prerelease --preid canary --force-publish",
     "lint-staged": "lint-staged"
@@ -27,6 +28,7 @@
   "standard": {
     "parser": "babel-eslint",
     "ignore": [
+      "**/*.d.ts",
       "**/node_modules/**",
       "examples/with-ioc/**",
       "examples/with-kea/**",
diff --git a/packages/next-server/tsconfig.json b/packages/next-server/tsconfig.json
index 1e365ba7..e0e366bc 100644
--- a/packages/next-server/tsconfig.json
+++ b/packages/next-server/tsconfig.json
@@ -1,10 +1,12 @@
 {
   "compilerOptions": {
+    "strict": true,
     "allowJs": true,
     "noEmit": true,
     "module": "esnext",
     "target": "ES2017",
     "esModuleInterop": true,
+    "moduleResolution": "node",
     "jsx": "react"
   }
 }
diff --git a/packages/next/build/babel/plugins/react-loadable-plugin.ts b/packages/next/build/babel/plugins/react-loadable-plugin.ts
index 131649c9..60b6ed5d 100644
--- a/packages/next/build/babel/plugins/react-loadable-plugin.ts
+++ b/packages/next/build/babel/plugins/react-loadable-plugin.ts
@@ -52,10 +52,12 @@ export default function ({ types: t }: {types: typeof BabelTypes}): PluginObj {
 
           if (
             callExpression.isMemberExpression() &&
-            callExpression.node.computed === false &&
-            callExpression.get('property').isIdentifier({ name: 'Map' })
+            callExpression.node.computed === false
           ) {
-            callExpression = callExpression.parentPath
+            const property = callExpression.get('property')
+            if (!Array.isArray(property) && property.isIdentifier({ name: 'Map' })) {
+              callExpression = callExpression.parentPath
+            }
           }
 
           if (!callExpression.isCallExpression()) return
diff --git a/packages/next/package.json b/packages/next/package.json
index f3fe8805..3701ccba 100644
--- a/packages/next/package.json
+++ b/packages/next/package.json
@@ -28,7 +28,8 @@
   "scripts": {
     "build": "taskr",
     "release": "taskr release",
-    "prepublish": "npm run release"
+    "prepublish": "npm run release",
+    "typescript": "tsc --noEmit"
   },
   "taskr": {
     "requires": [
@@ -91,6 +92,7 @@
     "react-dom": "^16.0.0"
   },
   "devDependencies": {
+    "@babel/parser": "7.2.0",
     "@taskr/clear": "1.1.0",
     "@taskr/esnext": "1.1.0",
     "@taskr/watch": "1.1.0",
@@ -100,6 +102,7 @@
     "@types/babel__template": "7.0.1",
     "@types/babel__traverse": "7.0.3",
     "@types/nanoid": "1.2.0",
+    "@types/node-fetch": "2.1.4",
     "@types/webpack": "4.4.20",
     "taskr": "1.1.0",
     "typescript": "3.1.6"
diff --git a/packages/next/tsconfig.json b/packages/next/tsconfig.json
index 2c685041..0c5457a5 100644
--- a/packages/next/tsconfig.json
+++ b/packages/next/tsconfig.json
@@ -1,20 +1,17 @@
 {
   "compilerOptions": {
+    "strict": true,
     "allowJs": true,
     "noEmit": true,
     "module": "esnext",
     "target": "ES2017",
     "esModuleInterop": true,
+    "moduleResolution": "node",
     "jsx": "react",
-    "strictNullChecks": true,
-    "noImplicitAny": true,
     "baseUrl": "../..",
     "paths": {
       "@babel/types": [
-        "babel-types/index.d.ts",
-        "@types/babel-types/index.d.ts",
-        "node_modules/@types/babel-types/index.d.ts",
-        "packages/next/node_modules/@types/babel-types/index.d.ts"
+        "@types/babel-types/index.d.ts"
       ]
     }
   }
diff --git a/packages/next/types/index.d.ts b/packages/next/types/index.d.ts
new file mode 100644
index 00000000..c938e9cf
--- /dev/null
+++ b/packages/next/types/index.d.ts
@@ -0,0 +1,3 @@
+declare module '@babel/plugin-transform-modules-commonjs';
+declare module 'next-server/next-config';
+declare module 'next-server/constants';