diff --git a/tests/__init__.py b/tests/__init__.py
index 0e6ad63..d04ebf2 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -261,6 +261,7 @@ def create_acls(session):
     for acl in [
             'issue_create', 'pull_request_merge', 'pull_request_comment',
             'issue_change_status', 'issue_comment', 'pull_request_close',
+            'pull_request_flag',
             ]:
         item = pagure.lib.model.ACL(
             name=acl,
@@ -273,7 +274,7 @@ def create_acls(session):
 
 def create_tokens_acl(session):
     """ Create some acls for the tokens. """
-    for aclid in range(6):
+    for aclid in range(7):
         item = pagure.lib.model.TokenAcl(
             token_id='aaabbbcccddd',
             acl_id=aclid + 1,
diff --git a/tests/test_progit_flask_api_fork.py b/tests/test_progit_flask_api_fork.py
index 6ea4a50..592a572 100644
--- a/tests/test_progit_flask_api_fork.py
+++ b/tests/test_progit_flask_api_fork.py
@@ -625,6 +625,154 @@ class PagureFlaskApiForktests(tests.Modeltests):
             self.session, project_id=1, requestid=1)
         self.assertEqual(len(request.comments), 1)
 
+    @patch('pagure.lib.notify.send_email')
+    def test_api_pull_request_add_flag(self, mockemail):
+        """ Test the api_pull_request_add_flag method of the flask api. """
+        mockemail.return_value = True
+
+        tests.create_projects(self.session)
+        tests.create_tokens(self.session)
+        tests.create_acls(self.session)
+        tests.create_tokens_acl(self.session)
+
+        headers = {'Authorization': 'token aaabbbcccddd'}
+
+        # Invalid project
+        output = self.app.post(
+            '/api/0/foo/pull-request/1/flag', headers=headers)
+        self.assertEqual(output.status_code, 404)
+        data = json.loads(output.data)
+        self.assertDictEqual(
+            data,
+            {
+              "error": "Project not found",
+              "error_code": "ENOPROJECT",
+            }
+        )
+
+        # Valid token, wrong project
+        output = self.app.post(
+            '/api/0/test2/pull-request/1/flag', headers=headers)
+        self.assertEqual(output.status_code, 401)
+        data = json.loads(output.data)
+        self.assertDictEqual(
+            data,
+            {
+              "error": "Invalid or expired token. Please visit " \
+                  "https://pagure.org/ to get or renew your API token.",
+              "error_code": "EINVALIDTOK",
+            }
+        )
+
+        # No input
+        output = self.app.post(
+            '/api/0/test/pull-request/1/flag', headers=headers)
+        self.assertEqual(output.status_code, 404)
+        data = json.loads(output.data)
+        self.assertDictEqual(
+            data,
+            {
+              "error": "Pull-Request not found",
+              "error_code": "ENOREQ",
+            }
+        )
+
+        # Create a pull-request
+        repo = pagure.lib.get_project(self.session, 'test')
+        forked_repo = pagure.lib.get_project(self.session, 'test')
+        msg = pagure.lib.new_pull_request(
+            session=self.session,
+            repo_from=forked_repo,
+            branch_from='master',
+            repo_to=repo,
+            branch_to='master',
+            title='test pull-request',
+            user='pingou',
+            requestfolder=None,
+        )
+        self.session.commit()
+        self.assertEqual(msg, 'Request created')
+
+        # Check comments before
+        request = pagure.lib.search_pull_requests(
+            self.session, project_id=1, requestid=1)
+        self.assertEqual(len(request.flags), 0)
+
+        data = {
+            'username': 'Jenkins',
+            'percent': 100,
+            'url': 'http://jenkins.cloud.fedoraproject.org/',
+            'uid': 'jenkins_build_pagure_100+seed',
+        }
+
+        # Incomplete request
+        output = self.app.post(
+            '/api/0/test/pull-request/1/flag', data=data, headers=headers)
+        self.assertEqual(output.status_code, 400)
+        data = json.loads(output.data)
+        self.assertDictEqual(
+            data,
+            {
+              "error": "Invalid or incomplete input submited",
+              "error_code": "EINVALIDREQ",
+            }
+        )
+
+        # No change
+        request = pagure.lib.search_pull_requests(
+            self.session, project_id=1, requestid=1)
+        self.assertEqual(len(request.flags), 0)
+
+        data = {
+            'username': 'Jenkins',
+            'percent': 0,
+            'comment': 'Tests failed',
+            'url': 'http://jenkins.cloud.fedoraproject.org/',
+            'uid': 'jenkins_build_pagure_100+seed',
+        }
+
+        # Valid request
+        output = self.app.post(
+            '/api/0/test/pull-request/1/flag', data=data, headers=headers)
+        self.assertEqual(output.status_code, 200)
+        data = json.loads(output.data)
+        self.assertDictEqual(
+            data,
+            {'message': 'Flag added'}
+        )
+
+        # One flag added
+        request = pagure.lib.search_pull_requests(
+            self.session, project_id=1, requestid=1)
+        self.assertEqual(len(request.flags), 1)
+        self.assertEqual(request.flags[0].comment, 'Tests failed')
+        self.assertEqual(request.flags[0].percent, 0)
+
+        # Update flag
+        data = {
+            'username': 'Jenkins',
+            'percent': 100,
+            'comment': 'Tests passed',
+            'url': 'http://jenkins.cloud.fedoraproject.org/',
+            'uid': 'jenkins_build_pagure_100+seed',
+        }
+
+        output = self.app.post(
+            '/api/0/test/pull-request/1/flag', data=data, headers=headers)
+        self.assertEqual(output.status_code, 200)
+        data = json.loads(output.data)
+        self.assertDictEqual(
+            data,
+            {'message': 'Flag updated'}
+        )
+
+        # One flag added
+        request = pagure.lib.search_pull_requests(
+            self.session, project_id=1, requestid=1)
+        self.assertEqual(len(request.flags), 1)
+        self.assertEqual(request.flags[0].comment, 'Tests passed')
+        self.assertEqual(request.flags[0].percent, 100)
+
 
 if __name__ == '__main__':
     SUITE = unittest.TestLoader().loadTestsFromTestCase(