diff --git a/server/app.js b/server/app.js
index e3e82c6..ef0b70e 100644
--- a/server/app.js
+++ b/server/app.js
@@ -6,7 +6,8 @@ const schema = require('./schema/schema');
 const app = express();
 
 app.use('/graphql', graphqlHTTP({
-  schema
+  schema,
+  graphiql: true
 }));
 
 app.listen(4000, () => {
diff --git a/server/schema/schema.js b/server/schema/schema.js
index cae4a48..3a90c94 100644
--- a/server/schema/schema.js
+++ b/server/schema/schema.js
@@ -28,7 +28,7 @@ const RootQuery = new GraphQLObjectType({
   fields: {
     book: {
       type: BookType,
-      args: { id: { GraphQLString } },
+      args: { id: { type: GraphQLString } },
       resolve (parent, { id }) {
         return _.find(books, { id });
       }