diff --git a/lib/index.js b/lib/index.js
index 26e0980..1b6bcae 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -62,7 +62,7 @@ var schemaFromEndpoints = function schemaFromEndpoints(endpoints, proxyUrl, head
 var resolver = function resolver(endpoint, proxyUrl) {
   var customHeaders = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
   return function () {
-    var _ref = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee(_, args, opts) {
+    var _ref = (0, _asyncToGenerator3.default)( /*#__PURE__*/_regenerator2.default.mark(function _callee(_, args, opts) {
       var proxy, req, res;
       return _regenerator2.default.wrap(function _callee$(_context) {
         while (1) {
@@ -113,7 +113,7 @@ var getFields = function getFields(endpoints, isMutation, gqlTypes, proxyUrl, he
 };
 
 var build = function () {
-  var _ref2 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee2(swaggerPath) {
+  var _ref2 = (0, _asyncToGenerator3.default)( /*#__PURE__*/_regenerator2.default.mark(function _callee2(swaggerPath) {
     var proxyUrl = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : null;
     var headers = arguments[2];
     var swaggerSchema, refs, endpoints, schema;
diff --git a/lib/swagger.js b/lib/swagger.js
index a14d647..fe4beaa 100644
--- a/lib/swagger.js
+++ b/lib/swagger.js
@@ -58,7 +58,7 @@ var getSuccessResponse = function getSuccessResponse(responses) {
 };
 
 var loadSchema = exports.loadSchema = function () {
-  var _ref = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee(pathToSchema) {
+  var _ref = (0, _asyncToGenerator3.default)( /*#__PURE__*/_regenerator2.default.mark(function _callee(pathToSchema) {
     return _regenerator2.default.wrap(function _callee$(_context) {
       while (1) {
         switch (_context.prev = _context.next) {
@@ -84,7 +84,7 @@ var loadSchema = exports.loadSchema = function () {
 }();
 
 var loadRefs = exports.loadRefs = function () {
-  var _ref2 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee2(pathToSchema) {
+  var _ref2 = (0, _asyncToGenerator3.default)( /*#__PURE__*/_regenerator2.default.mark(function _callee2(pathToSchema) {
     return _regenerator2.default.wrap(function _callee2$(_context2) {
       while (1) {
         switch (_context2.prev = _context2.next) {
diff --git a/lib/typeMap.js b/lib/typeMap.js
index fbc951a..8ed3c94 100644
--- a/lib/typeMap.js
+++ b/lib/typeMap.js
@@ -135,23 +135,28 @@ var getTypeFields = exports.getTypeFields = function getTypeFields(jsonSchema, t
   }
   return function () {
     return _lodash2.default.mapValues(jsonSchema.properties || {}, function (propertySchema, propertyName) {
+      var baseType = jsonSchemaTypeToGraphQL(title, propertySchema, propertyName, isInputType, gqlTypes);
+      var type = jsonSchema.required && jsonSchema.required.includes(propertyName) ? graphql.GraphQLNonNull(baseType) : baseType;
       return {
         description: propertySchema.description,
-        type: jsonSchemaTypeToGraphQL(title, propertySchema, propertyName, isInputType, gqlTypes)
+        type: type
       };
     });
   };
 };
 
 var jsonSchemaTypeToGraphQL = function jsonSchemaTypeToGraphQL(title, jsonSchema, schemaName, isInputType, gqlTypes) {
-  if (jsonSchema.$ref) {
-    return getExistingType(jsonSchema.$ref, isInputType, gqlTypes);
-  } else if (isObjectType(jsonSchema)) {
-    return createGQLObject(jsonSchema, title + '_' + schemaName, isInputType, gqlTypes);
-  } else if (jsonSchema.type) {
-    return getPrimitiveTypes(jsonSchema);
-  }
-  throw new Error("Don't know how to handle schema " + (0, _stringify2.default)(jsonSchema) + ' without type and schema');
+  var baseType = function () {
+    if (jsonSchema.$ref) {
+      return getExistingType(jsonSchema.$ref, isInputType, gqlTypes);
+    } else if (isObjectType(jsonSchema)) {
+      return createGQLObject(jsonSchema, title + '_' + schemaName, isInputType, gqlTypes);
+    } else if (jsonSchema.type) {
+      return getPrimitiveTypes(jsonSchema);
+    }
+    throw new Error("Don't know how to handle schema " + (0, _stringify2.default)(jsonSchema) + ' without type and schema');
+  }();
+  return jsonSchema.required ? graphql.GraphQLNonNull(baseType) : baseType;
 };
 
 var getPrimitiveTypes = function getPrimitiveTypes(jsonSchema) {
diff --git a/src/typeMap.js b/src/typeMap.js
index 6a9cb8e..1e06d38 100644
--- a/src/typeMap.js
+++ b/src/typeMap.js
@@ -112,22 +112,27 @@ export const getTypeFields = (jsonSchema: JSONSchemaType, title: string, isInput
   }
   return () =>
     _.mapValues(jsonSchema.properties || {}, (propertySchema, propertyName) => {
+      const baseType = jsonSchemaTypeToGraphQL(title, propertySchema, propertyName, isInputType, gqlTypes);
+      const type = jsonSchema.required && jsonSchema.required.includes(propertyName) ? graphql.GraphQLNonNull(baseType) : baseType;
       return {
         description: propertySchema.description,
-        type: jsonSchemaTypeToGraphQL(title, propertySchema, propertyName, isInputType, gqlTypes)
+        type
       };
     });
 };
 
 const jsonSchemaTypeToGraphQL = (title: string, jsonSchema: JSONSchemaType, schemaName: string, isInputType: boolean, gqlTypes: GraphQLTypeMap) => {
-  if (jsonSchema.$ref) {
-    return getExistingType(jsonSchema.$ref, isInputType, gqlTypes);
-  } else if (isObjectType(jsonSchema)) {
-    return createGQLObject(jsonSchema, title + '_' + schemaName, isInputType, gqlTypes);
-  } else if (jsonSchema.type) {
-    return getPrimitiveTypes(jsonSchema);
-  }
-  throw new Error("Don't know how to handle schema " + JSON.stringify(jsonSchema) + ' without type and schema');
+  const baseType = (() => {
+    if (jsonSchema.$ref) {
+      return getExistingType(jsonSchema.$ref, isInputType, gqlTypes);
+    } else if (isObjectType(jsonSchema)) {
+      return createGQLObject(jsonSchema, title + '_' + schemaName, isInputType, gqlTypes);
+    } else if (jsonSchema.type) {
+      return getPrimitiveTypes(jsonSchema);
+    }
+    throw new Error("Don't know how to handle schema " + JSON.stringify(jsonSchema) + ' without type and schema');
+  })();
+  return jsonSchema.required ? graphql.GraphQLNonNull(baseType) : baseType;
 };
 
 const getPrimitiveTypes = (jsonSchema: JSONSchemaType): GraphQLScalarType => {
diff --git a/src/types.js b/src/types.js
index 600e3ff..31f29f9 100644
--- a/src/types.js
+++ b/src/types.js
@@ -48,7 +48,8 @@ export type JSONSchemaType = {
   type?: string,
   properties?: Array<string>,
   title?: string,
-  description?: string
+  description?: string,
+  required?: boolean | Array<string>
 }
 
 export type SwaggerSchema = {
diff --git a/test/fixtures/petstore.graphql b/test/fixtures/petstore.graphql
index b557ce8..c689007 100644
--- a/test/fixtures/petstore.graphql
+++ b/test/fixtures/petstore.graphql
@@ -59,27 +59,27 @@ type logoutUser {
 }
 
 type Mutation {
-  addPet(body: PetInput): addPet
-  updatePet(body: PetInput): updatePet
-  updatePetWithForm(petId: String, name: String, status: String): updatePetWithForm
-  deletePet(api_key: String, petId: String): deletePet
-  placeOrder(body: OrderInput): Order
+  addPet(body: PetInput!): addPet
+  updatePet(body: PetInput!): updatePet
+  updatePetWithForm(petId: String!, name: String, status: String): updatePetWithForm
+  deletePet(api_key: String, petId: String!): deletePet
+  placeOrder(body: OrderInput!): Order
 
   """
   For valid response try integer IDs with positive integer value. Negative or non-integer values will generate API errors
   """
-  deleteOrder(orderId: String): deleteOrder
+  deleteOrder(orderId: String!): deleteOrder
 
   """This can only be done by the logged in user."""
-  createUser(body: UserInput): createUser
-  createUsersWithArrayInput(body: param_createUsersWithArrayInput_bodyInput): createUsersWithArrayInput
-  createUsersWithListInput(body: param_createUsersWithListInput_bodyInput): createUsersWithListInput
+  createUser(body: UserInput!): createUser
+  createUsersWithArrayInput(body: param_createUsersWithArrayInput_bodyInput!): createUsersWithArrayInput
+  createUsersWithListInput(body: param_createUsersWithListInput_bodyInput!): createUsersWithListInput
 
   """This can only be done by the logged in user."""
-  updateUser(username: String, body: UserInput): updateUser
+  updateUser(username: String!, body: UserInput!): updateUser
 
   """This can only be done by the logged in user."""
-  deleteUser(username: String): deleteUser
+  deleteUser(username: String!): deleteUser
 }
 
 type Order {
@@ -119,8 +119,8 @@ input param_createUsersWithListInput_bodyInput {
 type Pet {
   id: String
   category: Category
-  name: String
-  photoUrls: [String]
+  name: String!
+  photoUrls: [String]!
   tags: [Tag]
 
   """pet status in the store"""
@@ -130,8 +130,8 @@ type Pet {
 input PetInput {
   id: String
   category: CategoryInput
-  name: String
-  photoUrls: [String]
+  name: String!
+  photoUrls: [String]!
   tags: [TagInput]
 
   """pet status in the store"""
@@ -140,15 +140,15 @@ input PetInput {
 
 type Query {
   """Multiple status values can be provided with comma separated strings"""
-  findPetsByStatus(status: [String]): [Pet]
+  findPetsByStatus(status: [String]!): [Pet]
 
   """
   Muliple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
   """
-  findPetsByTags(tags: [String]): [Pet]
+  findPetsByTags(tags: [String]!): [Pet]
 
   """Returns a single pet"""
-  getPetById(petId: String): Pet
+  getPetById(petId: String!): Pet
 
   """Returns a map of status codes to quantities"""
   getInventory: getInventory
@@ -156,10 +156,10 @@ type Query {
   """
   For valid response try integer IDs with value >= 1 and <= 10. Other values will generated exceptions
   """
-  getOrderById(orderId: String): Order
-  loginUser(username: String, password: String): loginUser
+  getOrderById(orderId: String!): Order
+  loginUser(username: String!, password: String!): loginUser
   logoutUser: logoutUser
-  getUserByName(username: String): User
+  getUserByName(username: String!): User
 }
 
 type Tag {