diff --git a/.circleci/config.yml b/.circleci/config.yml
index 42b2b66..01513c2 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,11 +1,9 @@
 version: 2
-jobs:
-  build:
-    docker:
-      - image: circleci/node
+references: 
+  run_tests: &run_tests
     steps:
       - checkout
-      - run: sudo npm install -g yarn semantic-release@12.0.0
+      - run: sudo npm install -g yarn
       - run: yarn install
       - run:
           name: test
@@ -21,7 +19,41 @@ jobs:
       - store_artifacts:
           path: coverage
           prefix: coverage
+
+jobs:
+  build-node4:
+    docker:
+      - image: circleci/node:4
+    <<: *run_tests
+  build-node6:
+    docker:
+      - image: circleci/node:6
+    <<: *run_tests
+  build-node8:
+    docker:
+      - image: circleci/node
+    <<: *run_tests
+  release:
+    docker: 
+      - image: circleci/node
+    steps: 
+      - checkout
+      - run: sudo npm install -g yarn semantic-release@12.0.0
+      - run: yarn install
       - run: semantic-release
       - run: yarn docs
       # needs proper NOW setup first
       # - run: yarn docs:publish
+
+workflows:
+  version: 2
+  build:
+    jobs:
+      - build-node4
+      - build-node6
+      - build-node8
+      - release:
+          requires: 
+            - build-node4
+            - build-node6
+            - build-node8
diff --git a/package.json b/package.json
index 3d59fcf..d3fefcb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,9 @@
 {
   "name": "graphql-import",
   "version": "0.0.0-semantic-release",
+  "engines": {
+    "node": ">=4.0.0"
+  },
   "license": "MIT",
   "repository": "git@github.com:graphcool/graphql-import.git",
   "files": [
diff --git a/src/definition.ts b/src/definition.ts
index 2863ace..e9f2b2a 100644
--- a/src/definition.ts
+++ b/src/definition.ts
@@ -1,4 +1,4 @@
-import { keyBy, uniqBy } from 'lodash'
+import { keyBy, uniqBy, includes } from 'lodash'
 import {
   DocumentNode,
   TypeDefinitionNode,
@@ -147,7 +147,7 @@ function collectNewTypeDefinitions(
     // collect missing argument input types
     if (
       !definitionPool.some(d => d.name.value === nodeTypeName) &&
-      !builtinTypes.includes(nodeTypeName)
+      !includes(builtinTypes, nodeTypeName)
     ) {
       const argTypeMatch = schemaMap[nodeTypeName]
       if (!argTypeMatch) {
@@ -165,7 +165,7 @@ function collectNewTypeDefinitions(
     const directiveName = directive.name.value
     if (
       !definitionPool.some(d => d.name.value === directiveName) &&
-      !builtinDirectives.includes(directiveName)
+      !includes(builtinDirectives, directiveName)
     ) {
       const directive = schemaMap[directiveName] as DirectiveDefinitionNode
       if (!directive) {
diff --git a/src/index.ts b/src/index.ts
index 8a63a6c..559d009 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,6 @@
 import * as fs from 'fs'
 import { DefinitionNode, parse, print, TypeDefinitionNode, GraphQLObjectType, ObjectTypeDefinitionNode, DocumentNode, Kind } from 'graphql'
-import { flatten, groupBy } from 'lodash'
+import { flatten, groupBy, includes } from 'lodash'
 import * as path from 'path'
 
 import {
@@ -88,13 +88,13 @@ export function importSchema(schema: string, schemas?: { [key: string]: string }
   // And should always be in the first set, to make sure they
   // are not filtered out.
   const typesToFilter = ['Query', 'Mutation', 'Subscription']
-  const firstTypes = flatten(typeDefinitions).filter(d => typesToFilter.includes(d.name.value))
-  const otherFirstTypes = typeDefinitions[0].filter(d => !typesToFilter.includes(d.name.value))
+  const firstTypes = flatten(typeDefinitions).filter(d => includes(typesToFilter, d.name.value))
+  const otherFirstTypes = typeDefinitions[0].filter(d => !includes(typesToFilter, d.name.value))
   const firstSet = otherFirstTypes.concat(firstTypes)
   const processedTypeNames = []
   const mergedFirstTypes = []
   for (const type of firstSet) {
-    if (!processedTypeNames.includes(type.name.value)) {
+    if (!includes(processedTypeNames, type.name.value)) {
       processedTypeNames.push(type.name.value)
       mergedFirstTypes.push(type)
     } else {
@@ -232,10 +232,10 @@ function filterImportedDefinitions(
 
   const filteredDefinitions = filterTypeDefinitions(typeDefinitions)
 
-  if (imports.includes('*')) {
+  if (includes(imports, '*')) {
     return filteredDefinitions
   } else {
-    const result = filteredDefinitions.filter(d => imports.map(i => i.split('.')[0]).includes(d.name.value))
+    const result = filteredDefinitions.filter(d => includes(imports.map(i => i.split('.')[0]), d.name.value))
     const fieldImports = imports
       .filter(i => i.split('.').length > 1)
     const groupedFieldImports = groupBy(fieldImports, x => x.split('.')[0])
@@ -244,7 +244,7 @@ function filterImportedDefinitions(
       const fields = groupedFieldImports[rootType].map(x => x.split('.')[1]);
       (filteredDefinitions.find(def => def.name.value === rootType) as ObjectTypeDefinitionNode).fields =
         (filteredDefinitions.find(def => def.name.value === rootType) as ObjectTypeDefinitionNode).fields
-          .filter(f => fields.includes(f.name.value) || fields.includes('*'))
+          .filter(f => includes(fields, f.name.value) || includes(fields, '*'))
     }
 
     return result
@@ -270,6 +270,6 @@ function filterTypeDefinitions(
     'InputObjectTypeDefinition'
   ]
   return definitions
-    .filter(d => validKinds.includes(d.kind))
+    .filter(d => includes(validKinds, d.kind))
     .map(d => d as ValidDefinitionNode)
 }