diff --git a/gitlab/exceptions.py b/gitlab/exceptions.py
index 0822d3e58..5b7b75c24 100644
--- a/gitlab/exceptions.py
+++ b/gitlab/exceptions.py
@@ -170,6 +170,10 @@ class GitlabMRForbiddenError(GitlabOperationError):
     pass
 
 
+class GitlabMRApprovalError(GitlabOperationError):
+    pass
+
+
 class GitlabMRClosedError(GitlabOperationError):
     pass
 
diff --git a/gitlab/v4/objects.py b/gitlab/v4/objects.py
index c3714d8c4..af61488b8 100644
--- a/gitlab/v4/objects.py
+++ b/gitlab/v4/objects.py
@@ -2277,23 +2277,46 @@ def changes(self, **kwargs):
         path = '%s/%s/changes' % (self.manager.path, self.get_id())
         return self.manager.gitlab.http_get(path, **kwargs)
 
-    @cli.register_custom_action('ProjectMergeRequest')
-    @exc.on_http_error(exc.GitlabListError)
-    def pipelines(self, **kwargs):
-        """List the merge request pipelines.
+    @cli.register_custom_action('ProjectMergeRequest', tuple(), ('sha'))
+    @exc.on_http_error(exc.GitlabMRApprovalError)
+    def approve(self, sha=None, **kwargs):
+        """Approve the merge request.
 
         Args:
+            sha (str): Head SHA of MR
             **kwargs: Extra options to send to the server (e.g. sudo)
 
         Raises:
             GitlabAuthenticationError: If authentication is not correct
-            GitlabListError: If the list could not be retrieved
+            GitlabMRApprovalError: If the approval failed
+        """
+        path = '%s/%s/approve' % (self.manager.path, self.get_id())
+        data = {}
+        if sha:
+            data['sha'] = sha
 
-        Returns:
-            RESTObjectList: List of changes
+        server_data = self.manager.gitlab.http_post(path, post_data=data,
+                                                    **kwargs)
+        self._update_attrs(server_data)
+
+    @cli.register_custom_action('ProjectMergeRequest')
+    @exc.on_http_error(exc.GitlabMRApprovalError)
+    def unapprove(self, **kwargs):
+        """Unapprove the merge request.
+
+        Args:
+            **kwargs: Extra options to send to the server (e.g. sudo)
+
+        Raises:
+            GitlabAuthenticationError: If authentication is not correct
+            GitlabMRApprovalError: If the unapproval failed
         """
-        path = '%s/%s/pipelines' % (self.manager.path, self.get_id())
-        return self.manager.gitlab.http_get(path, **kwargs)
+        path = '%s/%s/unapprove' % (self.manager.path, self.get_id())
+        data = {}
+
+        server_data = self.manager.gitlab.http_post(path, post_data=data,
+                                                    **kwargs)
+        self._update_attrs(server_data)
 
     @cli.register_custom_action('ProjectMergeRequest', tuple(),
                                 ('merge_commit_message',