diff --git a/files/cert2json.py b/files/cert2json.py
index a6fb2e8641a4d06e7217f703db2c35600c492153..41c51bf9eb9d646f8a0dbccf4de471d04fd1302d 100755
--- a/files/cert2json.py
+++ b/files/cert2json.py
@@ -62,7 +62,7 @@ if __name__ == "__main__":
                     domains_joined = '\n  - '.join(domains_modified)
                     txt_line_out = "  domains:\n  - " + domains_joined
                 elif "Expiry Date: " in txt_line:
-                    txt_line_out = re.sub('.*Expiry Date: .*(', '  expiry_date: "', txt_line)
+                    txt_line_out = re.sub('.*Expiry Date: .*\(', '  expiry_date: "', txt_line)
                     txt_line_out = txt_line_out.replace(')', '') + '"'
                 else:
                     txt_line_out = None