diff --git a/docs/README.md b/docs/README.md
index 7217acd28..98b199f02 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -10,10 +10,19 @@ Compilation into HTML
 
 To compile this documentation :
 
-1. Install [sphinx-doc](http://sphinx-doc.org) (eg. pip install sphinx &  pip install sphinx_rtd_theme)
+1. Install [sphinx-doc](http://sphinx-doc.org)
+    ``` bash
+            $ virtualenv .venv # creation of the virtual env (only the first time)
+            $ source .venv/bin/activate # activate the virtual env
+    (.venv) $ pip install -r requirements.txt
+    ```
 2. Install submodules : $ git submodule update --init;
 3. run `make html` from the root directory
 4. The base file is located on build/html/index.html
+    ``` bash
+    $ cd build/html
+    $ python -m http.server 8888 # will serve the site on the port 8888
+    ```
 
 Contribute
 ===========
diff --git a/src/Bundle/ChillMainBundle/Notification/Mailer.php b/src/Bundle/ChillMainBundle/Notification/Mailer.php
index 82d8822af..73debaae5 100644
--- a/src/Bundle/ChillMainBundle/Notification/Mailer.php
+++ b/src/Bundle/ChillMainBundle/Notification/Mailer.php
@@ -104,7 +104,7 @@ class Mailer
      * @param \User $to
      * @param array $subject Subject of the message [ 0 => $message (required), 1 => $parameters (optional), 3 => $domain (optional) ]
      * @param array $bodies The bodies. An array where keys are the contentType and values the bodies
-     * @param \callable $callback a callback to customize the message (add attachment, etc.)
+     * @param callable $callback a callback to customize the message (add attachment, etc.)
      */
     public function sendNotification(
         $recipient,
diff --git a/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php b/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php
index bc2254ec9..1c526aa1e 100644
--- a/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php
+++ b/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php
@@ -152,7 +152,7 @@ class SingleTaskController extends AbstractController
         $em = $this->getDoctrine()->getManager();
         $task = $em->getRepository(SingleTask::class)->find($id);
 
-        if (!is_null($task->getPerson() === !null)) {
+        if ($task->getPerson() !== null) {
             $personId = $task->getPerson()->getId();
 
             if ($personId === null) {
@@ -206,7 +206,7 @@ class SingleTaskController extends AbstractController
         $em = $this->getDoctrine()->getManager();
         $task = $em->getRepository(SingleTask::class)->find($id);
 
-        if (!is_null($task->getPerson() === !null)) {
+        if ($task->getPerson() !== null) {
             $personId = $task->getPerson()->getId();
             if ($personId === null) {
                 return new Response("You must provide a person_id", Response::HTTP_BAD_REQUEST);
@@ -303,8 +303,7 @@ class SingleTaskController extends AbstractController
             throw $this->createNotFoundException('Unable to find Task entity.');
         }
 
-        if (!is_null($task->getPerson() === !null)) {
-
+        if ($task->getPerson() !== null) {
             $personId = $task->getPerson()->getId();
             if ($personId === null) {
                 return new Response("You must provide a person_id", Response::HTTP_BAD_REQUEST);