diff --git a/python/wpt/exporter/__init__.py b/python/wpt/exporter/__init__.py
index b2df5675598..b89f1fa2b99 100644
--- a/python/wpt/exporter/__init__.py
+++ b/python/wpt/exporter/__init__.py
@@ -180,7 +180,7 @@ class WPTSync:
                 wpt_branch_name_from_servo_pr_number(servo_pr.number)
             )
             upstream_pr = self.wpt.get_open_pull_request_for_branch(
-                downstream_wpt_branch
+                self.github_username, downstream_wpt_branch
             )
             if upstream_pr:
                 logging.info(
diff --git a/python/wpt/exporter/github.py b/python/wpt/exporter/github.py
index 824bcb997f4..c46f9d86700 100644
--- a/python/wpt/exporter/github.py
+++ b/python/wpt/exporter/github.py
@@ -72,7 +72,9 @@ class GithubRepository:
         return GithubBranch(self, name)
 
     def get_open_pull_request_for_branch(
-        self, branch: GithubBranch
+        self,
+        github_username: str,
+        branch: GithubBranch
     ) -> Optional[PullRequest]:
         """If this repository has an open pull request with the
         given source head reference targeting the main branch,
@@ -82,7 +84,7 @@ class GithubRepository:
             "is:pr",
             "state:open",
             f"repo:{self.repo}",
-            f"author:{branch.repo.org}",
+            f"author:{github_username}",
             f"head:{branch.name}",
         ])
         response = authenticated(self.sync, "GET", f"search/issues?q={params}")
diff --git a/python/wpt/test.py b/python/wpt/test.py
index e6231f8d0a0..adf48a0d7c2 100644
--- a/python/wpt/test.py
+++ b/python/wpt/test.py
@@ -140,12 +140,11 @@ class MockGitHubAPIServer():
 
             assert params["is"] == "pr"
             assert params["state"] == "open"
-            assert "author" in params
             assert "head" in params
-            head_ref = f"{params['author']}:{params['head']}"
+            head_ref = f":{params['head']}"
 
             for pull_request in self.pulls:
-                if pull_request.head == head_ref:
+                if pull_request.head.endswith(head_ref):
                     return json.dumps({
                         "total_count": 1,
                         "items": [{