diff --git a/tools/accept_upstream.py b/tools/accept_upstream.py
index bc8226df..8aacd673 100755
--- a/tools/accept_upstream.py
+++ b/tools/accept_upstream.py
@@ -53,7 +53,8 @@ if __name__ == '__main__':
 
     # Fetch commit information
     commits = http.get(f'https://api.github.com/repos/{upstream}/pulls/{pr}/commits').json()
-    author = json.loads(os.environ.get("override_author")) or commits[-1]['commit']['author']
+    override_author = os.environ.get("override_author")
+    author = json.loads(override_author) if override_author else commits[-1]['commit']['author']
 
     # Create commit message
     title = info["title"].replace('"', '\\"')