diff --git a/doc/README.md b/doc/README.md
index 04fcd7a3885..ba33a60c503 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -12,8 +12,10 @@ APIs:
   * [Comments](gists/comments.md)
 * [Integrations](integrations.md)
 * [Issues](issues.md)
+  * [Assignees](issue/assignees.md)
   * [Comments](issue/comments.md)
   * [Labels](issue/labels.md)
+  * [Milestones](issue/milestones.md)
 * Miscellaneous
   * [Emojis](miscellaneous/emojis.md)
   * [Gitignore](miscellaneous/gitignore.md)
diff --git a/doc/issue/assignees.md b/doc/issue/assignees.md
new file mode 100644
index 00000000000..035ea8ddcd7
--- /dev/null
+++ b/doc/issue/assignees.md
@@ -0,0 +1,28 @@
+## Issues / Assignees API
+[Back to the "Issues API"](../issues.md) | [Back to the navigation](../README.md)
+
+Wraps [GitHub Issue Assignees API](https://developer.github.com/v3/issues/assignees/).
+
+### List all available assignees
+
+```php
+$assignees = $client->api('issue')->assignees()->listAvailable('KnpLabs', 'php-github-api');
+```
+
+### Check if a user is an available assignee
+
+```php
+$info = $client->api('issue')->assignees()->check('KnpLabs', 'php-github-api', 'test-user);
+```
+
+### Add assignee
+
+```php
+$client->api('issue')->assignees()->add('KnpLabs', 'php-github-api', 4, ['assignees' => 'test-user]);
+```
+
+### Remove assignee
+
+```php
+$client->api('issue')->assignees()->remove('KnpLabs', 'php-github-api', 4, ['assignees' => 'test-user]);
+```
diff --git a/doc/issue/labels.md b/doc/issue/labels.md
index 2b35848bccb..828726f96ed 100644
--- a/doc/issue/labels.md
+++ b/doc/issue/labels.md
@@ -12,6 +12,12 @@ $labels = $client->api('issue')->labels()->all('KnpLabs', 'php-github-api');
 List all project labels by username and repo.
 Returns an array of project labels.
 
+### Get a single label
+
+```php
+$label = $client->api('issue')->labels()->all('KnpLabs', 'php-github-api', 'label1');
+```
+
 ### Create a label
 
 ```php
diff --git a/doc/issues.md b/doc/issues.md
index e2804277d35..3f26bab5ad6 100644
--- a/doc/issues.md
+++ b/doc/issues.md
@@ -84,3 +84,15 @@ $client->api('issue')->all('KnpLabs', 'php-github-api', array('labels' => 'label
 ```
 
 Returns an array of issues matching the given label.
+
+### Lock an issue discussion
+
+```php
+$client->api('issue')->lock('KnpLabs', 'php-github-api', 4);
+```
+
+### Unlock an issue discussion
+
+```php
+$client->api('issue')->unlock('KnpLabs', 'php-github-api', 4);
+```
diff --git a/lib/Github/Api/Issue.php b/lib/Github/Api/Issue.php
index f1f41d92ed1..4c30783473d 100644
--- a/lib/Github/Api/Issue.php
+++ b/lib/Github/Api/Issue.php
@@ -2,6 +2,7 @@
 
 namespace Github\Api;
 
+use Github\Api\Issue\Assignees;
 use Github\Api\Issue\Comments;
 use Github\Api\Issue\Events;
 use Github\Api\Issue\Labels;
@@ -132,6 +133,38 @@ public function update($username, $repository, $id, array $params)
         return $this->patch('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/issues/'.rawurlencode($id), $params);
     }
 
+    /**
+     * Lock an issue. Users with push access can lock an issue's conversation.
+     *
+     * @link https://developer.github.com/v3/issues/#lock-an-issue
+     *
+     * @param string $username
+     * @param string $repository
+     * @param string $id
+     *
+     * @return string
+     */
+    public function lock($username, $repository, $id)
+    {
+        return $this->put('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/issues/'.rawurlencode($id).'/lock');
+    }
+
+    /**
+     * Unlock an issue. Users with push access can unlock an issue's conversation.
+     *
+     * @link https://developer.github.com/v3/issues/#lock-an-issue
+     *
+     * @param string $username
+     * @param string $repository
+     * @param string $id
+     *
+     * @return string
+     */
+    public function unlock($username, $repository, $id)
+    {
+        return $this->delete('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/issues/'.rawurlencode($id).'/lock');
+    }
+
     /**
      * List an issue comments.
      *
@@ -179,4 +212,16 @@ public function milestones()
     {
         return new Milestones($this->client);
     }
+
+    /**
+     * List all assignees.
+     *
+     * @link https://developer.github.com/v3/issues/assignees/
+     *
+     * @return Assignees
+     */
+    public function assignees()
+    {
+        return new Assignees($this->client);
+    }
 }
diff --git a/lib/Github/Api/Issue/Assignees.php b/lib/Github/Api/Issue/Assignees.php
new file mode 100644
index 00000000000..f304f7ab05a
--- /dev/null
+++ b/lib/Github/Api/Issue/Assignees.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace Github\Api\Issue;
+
+use Github\Api\AbstractApi;
+use Github\Exception\MissingArgumentException;
+
+class Assignees extends AbstractApi
+{
+    /**
+     * List all the available assignees to which issues may be assigned.
+     *
+     * @param string $username
+     * @param string $repository
+     * @param array  $parameters
+     *
+     * @return array
+     */
+    public function listAvailable($username, $repository, array $parameters = array())
+    {
+        return $this->get('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/assignees', $parameters);
+    }
+
+    /**
+     * Check to see if a particular user is an assignee for a repository.
+     *
+     * @link https://developer.github.com/v3/issues/assignees/#check-assignee
+     *
+     * @param string $username
+     * @param string $repository
+     * @param string $assignee
+     *
+     * @return array
+     */
+    public function check($username, $repository, $assignee)
+    {
+        return $this->get('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/assignees/' . rawurlencode($assignee));
+    }
+
+    /**
+     * Add assignees to an Issue
+     *
+     * @link https://developer.github.com/v3/issues/assignees/#add-assignees-to-an-issue
+     *
+     * @param string $username
+     * @param string $repository
+     * @param string $issue
+     * @param array  $parameters
+     *
+     * @return string
+     * @throws MissingArgumentException
+     */
+    public function add($username, $repository, $issue, array $parameters)
+    {
+        if (!isset($parameters['assignees'])) {
+            throw new MissingArgumentException('assignees');
+        }
+
+        return $this->post('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/issues/'.rawurlencode($issue).'/assignees', $parameters);
+    }
+
+    /**
+     * Remove assignees from an Issue
+     *
+     * @link https://developer.github.com/v3/issues/assignees/#remove-assignees-from-an-issue
+     *
+     * @param string $username
+     * @param string $repository
+     * @param string $issue
+     * @param array  $parameters
+     *
+     * @return string
+     * @throws MissingArgumentException
+     */
+    public function remove($username, $repository, $issue, array $parameters)
+    {
+        if (!isset($parameters['assignees'])) {
+            throw new MissingArgumentException('assignees');
+        }
+
+        return $this->delete('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/issues/'.rawurlencode($issue).'/assignees', $parameters);
+    }
+}
diff --git a/lib/Github/Api/Issue/Labels.php b/lib/Github/Api/Issue/Labels.php
index 8f27887acfb..fb0f52362e3 100644
--- a/lib/Github/Api/Issue/Labels.php
+++ b/lib/Github/Api/Issue/Labels.php
@@ -33,6 +33,22 @@ public function all($username, $repository, $issue = null)
         return $this->get($path);
     }
 
+    /**
+     * Get a single label.
+     *
+     * @link https://developer.github.com/v3/issues/labels/#get-a-single-label
+     *
+     * @param string $username
+     * @param string $repository
+     * @param string $label
+     *
+     * @return array
+     */
+    public function show($username, $repository, $label)
+    {
+        return $this->get('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/labels/'.rawurlencode($label));
+    }
+
     /**
      * Create a label for a repository.
      *
diff --git a/test/Github/Tests/Api/Issue/AssigneesTest.php b/test/Github/Tests/Api/Issue/AssigneesTest.php
new file mode 100644
index 00000000000..a3cfe0f6066
--- /dev/null
+++ b/test/Github/Tests/Api/Issue/AssigneesTest.php
@@ -0,0 +1,107 @@
+<?php
+
+namespace Github\Tests\Api\Issue;
+
+use Github\Api\Issue\Assignees;
+use Github\Tests\Api\TestCase;
+
+class AssigneesTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function shouldListAvailableAssignees()
+    {
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('get')
+            ->with('/repos/knplabs/php-github-api/assignees');
+
+        $api->listAvailable('knplabs', 'php-github-api');
+    }
+
+    /**
+     * @test
+     */
+    public function shouldCheckAssignee()
+    {
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('get')
+            ->with('/repos/knplabs/php-github-api/assignees/test-user');
+
+        $api->check('knplabs', 'php-github-api', 'test-user');
+    }
+
+    /**
+     * @test
+     * @expectedException \Github\Exception\MissingArgumentException
+     */
+    public function shouldNotAddAssigneeMissingParameter()
+    {
+        $data = array();
+
+        $api = $this->getApiMock();
+        $api->expects($this->never())
+            ->method('post');
+
+        $api->add('knplabs', 'php-github-api', 4, $data);
+    }
+
+    /**
+     * @test
+     */
+    public function shouldAddAssignee()
+    {
+        $data = array(
+            'assignees' => array('test-user')
+        );
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('post')
+            ->with('/repos/knplabs/php-github-api/issues/4/assignees', $data);
+
+        $api->add('knplabs', 'php-github-api', 4, $data);
+    }
+
+    /**
+     * @test
+     * @expectedException \Github\Exception\MissingArgumentException
+     */
+    public function shouldNotRemoveAssigneeMissingParameter()
+    {
+        $data = array();
+
+        $api = $this->getApiMock();
+        $api->expects($this->never())
+            ->method('delete');
+
+        $api->remove('knplabs', 'php-github-api', 4, $data);
+    }
+
+    /**
+     * @test
+     */
+    public function shouldRemoveAssignee()
+    {
+        $data = array(
+            'assignees' => array('test-user')
+        );
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('delete')
+            ->with('/repos/knplabs/php-github-api/issues/4/assignees', $data);
+
+        $api->remove('knplabs', 'php-github-api', 4, $data);
+    }
+
+    /**
+     * @return string
+     */
+    protected function getApiClass()
+    {
+        return Assignees::class;
+    }
+}
diff --git a/test/Github/Tests/Api/Issue/LabelsTest.php b/test/Github/Tests/Api/Issue/LabelsTest.php
index e6be19d27c3..5be4e21254d 100644
--- a/test/Github/Tests/Api/Issue/LabelsTest.php
+++ b/test/Github/Tests/Api/Issue/LabelsTest.php
@@ -58,6 +58,22 @@ public function shouldCreateLabel()
         $this->assertEquals($expectedValue, $api->create('KnpLabs', 'php-github-api', $data));
     }
 
+    /**
+     * @test
+     */
+    public function shouldGetSingleLabel()
+    {
+        $expectedValue = array(array('name' => 'label1'));
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('get')
+            ->with('/repos/KnpLabs/php-github-api/labels/label1')
+            ->will($this->returnValue($expectedValue));
+
+        $this->assertEquals($expectedValue, $api->show('KnpLabs', 'php-github-api', 'label1'));
+    }
+
     /**
      * @test
      */
diff --git a/test/Github/Tests/Api/IssueTest.php b/test/Github/Tests/Api/IssueTest.php
index 242a650a3e7..a8a40835b39 100644
--- a/test/Github/Tests/Api/IssueTest.php
+++ b/test/Github/Tests/Api/IssueTest.php
@@ -242,6 +242,36 @@ public function shouldGetMilestonesApiObject()
         $this->assertInstanceOf(\Github\Api\Issue\Milestones::class, $api->milestones());
     }
 
+    /**
+     * @test
+     */
+    public function shouldLockIssue()
+    {
+        $parameters = array();
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('put')
+            ->with('/repos/knplabs/php-github-api/issues/1/lock', $parameters);
+
+        $api->lock('knplabs', 'php-github-api', '1');
+    }
+
+    /**
+     * @test
+     */
+    public function shouldUnlockIssue()
+    {
+        $parameters = array();
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('delete')
+            ->with('/repos/knplabs/php-github-api/issues/1/lock', $parameters);
+
+        $api->unlock('knplabs', 'php-github-api', '1');
+    }
+
     /**
      * @return string
      */