diff --git a/tests/fakegithub.py b/tests/fakegithub.py
index 8e2f275eb9..2c226fe4fc 100644
--- a/tests/fakegithub.py
+++ b/tests/fakegithub.py
@@ -518,24 +518,6 @@ class FakePull(object):
         # with the head_sha as the only commit
         return [self.head]
 
-    def merge(self, commit_message=None, sha=None, merge_method=None):
-        conn = self._fake_pull_request.github
-        pr = self._fake_pull_request
-
-        # record that this got reported
-        conn.github_data.reports.append(
-            (pr.project, pr.number, 'merge', merge_method))
-        if conn.merge_failure:
-            raise Exception('Unknown merge failure')
-        if conn.merge_not_allowed_count > 0:
-            conn.merge_not_allowed_count -= 1
-            resp = ErrorResponse()
-            resp.status_code = 403
-            resp.message = 'Merge not allowed'
-            raise github3.exceptions.MethodNotAllowed(resp)
-        pr.setMerged(commit_message)
-        return True
-
     def as_dict(self):
         pr = self._fake_pull_request
         connection = pr.github
@@ -669,6 +651,31 @@ class FakeGithubSession(object):
 
         return FakeResponse(None, 404)
 
+    def put(self, url, data=None, headers=None, params=None, json=None):
+        # Handle pull request merge
+        match = re.match(r'.+/repos/(.+)/pulls/(\d+)/merge$', url)
+        if match:
+            project, pr_number = match.groups()
+            project = urllib.parse.unquote(project)
+            pr = self.client._data.pull_requests[int(pr_number)]
+            conn = pr.github
+
+            # record that this got reported
+            self.client._data.reports.append(
+                (pr.project, pr.number, 'merge', json["merge_method"]))
+            if conn.merge_failure:
+                raise Exception('Unknown merge failure')
+            if conn.merge_not_allowed_count > 0:
+                conn.merge_not_allowed_count -= 1
+                resp = ErrorResponse()
+                resp.status_code = 403
+                resp.message = 'Merge not allowed'
+                raise github3.exceptions.MethodNotAllowed(resp)
+            pr.setMerged(json["commit_message"])
+            return FakeResponse({"merged": True}, 200)
+
+        return FakeResponse(None, 404)
+
     def get_repo(self, request, params=None):
         org, project, request = request.split('/', 2)
         project_name = '{}/{}'.format(org, project)
diff --git a/zuul/driver/github/githubconnection.py b/zuul/driver/github/githubconnection.py
index 7547682323..f0452f8fe0 100644
--- a/zuul/driver/github/githubconnection.py
+++ b/zuul/driver/github/githubconnection.py
@@ -1872,17 +1872,31 @@ class GithubConnection(BaseConnection):
                   method='merge', zuul_event_id=None):
         log = get_annotated_logger(self.log, zuul_event_id)
         github = self.getGithubClient(project, zuul_event_id=zuul_event_id)
-        owner, proj = project.split('/')
-        pull_request = github.pull_request(owner, proj, pr_number)
+        url = github.session.build_url("repos", project, "pulls",
+                                       str(pr_number), "merge")
+
+        payload = {
+            "merge_method": method,
+        }
+        if sha:
+            payload["sha"] = sha
+        if commit_message:
+            payload["commit_message"] = commit_message
+
         try:
-            result = pull_request.merge(commit_message=commit_message, sha=sha,
-                                        merge_method=method)
+            resp = github.session.put(url, json=payload)
+            resp.raise_for_status()
+            data = resp.json()
+            if not data:
+                result = False
+            else:
+                result = data["merged"]
         except Exception as e:
             raise MergeFailure('Pull request merge failed: %s' % e)
 
         if not result:
             raise MergeFailure('Pull request was not merged')
-        log.debug("Merged PR %s/%s#%s", owner, proj, pr_number)
+        log.debug("Merged PR %s#%s", project, pr_number)
 
     def _getCommit(self, repository, sha, retries=5):
         try: