diff --git a/front/src/components/Category.js b/front/src/components/Category.js
index d20a89d..043ce46 100644
--- a/front/src/components/Category.js
+++ b/front/src/components/Category.js
@@ -1,5 +1,7 @@
+// @flow
+
 import React, { Component } from 'react';
 
 class Category extends Component {
     
-}
\ No newline at end of file
+}
diff --git a/front/src/components/CategoryChild.js b/front/src/components/CategoryChild.js
index 02bf93c..731f122 100644
--- a/front/src/components/CategoryChild.js
+++ b/front/src/components/CategoryChild.js
@@ -1,3 +1,5 @@
+// @flow
+
 import React, { Component } from 'react';
 import * as T from '../types';
 import { fetchData } from '../utils/index';
@@ -31,8 +33,8 @@ class CategoryChild extends Component {
         <div>
           <h1>{ this.state.cat.title }</h1>
           <If condition={this.state.cat.description !== undefined}>
-             <div dangerouslySetInnerHTML=
-                  {{__html: this.state.cat.description.html}} />
+             <div dangerouslySetInnerHTML={{__html:
+                    this.state.cat.description.html}} />
           </If>
           <If condition={this.state.cat.items !== undefined}>
               { this.state.cat.items.map(i => item(i.uid, i.name)) }
diff --git a/front/src/components/GrandCategory.js b/front/src/components/GrandCategory.js
index fe008e6..0e2a011 100644
--- a/front/src/components/GrandCategory.js
+++ b/front/src/components/GrandCategory.js
@@ -1,3 +1,5 @@
+// @flow
+
 import React, { Component } from 'react';
 import { If } from 'jsx-control-statements';
 import R from 'ramda';
diff --git a/front/src/components/Home.js b/front/src/components/Home.js
index a5f445a..acdecc1 100644
--- a/front/src/components/Home.js
+++ b/front/src/components/Home.js
@@ -1,3 +1,5 @@
+// @flow
+
 import React, { Component } from 'react';
 import { GrandCategory } from './GrandCategory';
 import { Tiles } from './Tiles';
@@ -27,4 +29,4 @@ class Home extends Component {
     }
 }
 
-module.exports = { Home }
\ No newline at end of file
+module.exports = { Home }
diff --git a/front/src/components/NoMatch.js b/front/src/components/NoMatch.js
index 133aa7a..3ebff8c 100644
--- a/front/src/components/NoMatch.js
+++ b/front/src/components/NoMatch.js
@@ -1,3 +1,5 @@
+// @flow
+
 import React, { Component } from 'react';
 import { Link } from 'react-router-dom';
 
@@ -14,4 +16,4 @@ class NoMatch extends Component {
 
 module.exports = {
     NoMatch
-}
\ No newline at end of file
+}
diff --git a/front/src/components/Tiles.js b/front/src/components/Tiles.js
index a0f8520..91342ec 100644
--- a/front/src/components/Tiles.js
+++ b/front/src/components/Tiles.js
@@ -1,3 +1,5 @@
+// @flow
+
 import React, { Component } from 'react';
 
 // Tiles grouped into columns
@@ -27,4 +29,4 @@ class Tiles extends Component {
   }
 }
 
-module.exports = { Tiles }
\ No newline at end of file
+module.exports = { Tiles }
diff --git a/front/src/components/index.js b/front/src/components/index.js
index 98d4aac..4d8a946 100644
--- a/front/src/components/index.js
+++ b/front/src/components/index.js
@@ -10,4 +10,4 @@ module.exports = {
     CategoryChild,
     Home,
     NoMatch
-}
\ No newline at end of file
+}
diff --git a/front/src/types.js b/front/src/types.js
index ff50bc6..7a3464c 100644
--- a/front/src/types.js
+++ b/front/src/types.js
@@ -1,3 +1,4 @@
+// @flow
 
 export type Category = {
   uid   : string,
diff --git a/front/src/utils/fetchData.js b/front/src/utils/fetchData.js
index 0682cf7..4de4614 100644
--- a/front/src/utils/fetchData.js
+++ b/front/src/utils/fetchData.js
@@ -1,3 +1,4 @@
+// @flow
 
 function checkStatus(response) {
   if (response.status >= 200 && response.status < 300) {
@@ -22,4 +23,4 @@ function fetchData(url : string) : Promise<any> {
 
  module.exports = {
      fetchData
- }
\ No newline at end of file
+ }
diff --git a/front/src/utils/index.js b/front/src/utils/index.js
index 3f51f05..aacd9d2 100644
--- a/front/src/utils/index.js
+++ b/front/src/utils/index.js
@@ -2,4 +2,4 @@ import { fetchData } from './fetchData';
 
 module.exports = {
     fetchData
-}
\ No newline at end of file
+}