diff --git a/start.py b/start.py
index 433e23b..da40d1b 100644
--- a/start.py
+++ b/start.py
@@ -15,6 +15,7 @@ from docker import Client
 cert_path = '/data/haproxy'
 cert_file = cert_path + '/cert.pem'
 pid_file = '/haproxy.pid'
+max_age = 24 * 60 * 60
 delay = 10
 
 
@@ -128,8 +129,8 @@ def create_haproxy_cert():
 
     fullchain = read_file(youngest_directory + '/fullchain.pem')
     privkey = read_file(youngest_directory + '/privkey.pem')
-    write_file(cert_file, fullchain + privkey)
-    logging.info('file written')
+    return fullchain + privkey
+
 
 def create_cert_data_standalone(domains):
     if len(domains) == 0:
@@ -215,14 +216,32 @@ if __name__ == '__main__':
     t = threading.Thread(target=cert_watcher)
     t.start()
 
+    cert_cache = {}
     for line in client.events():
         line_str = line.decode("utf-8")
         event = json.loads(line_str)
 
-        if event['Action'] in ['start', 'stop']:
+        if event['Action'] in ['create']:
             # check if there is any domain name configured
             container_id = event['id']
             if len(list_domains.handle_container(client, container_id)) > 0:
                 resolved_domains = list_domains.get_resolving_domains_from_containers(client)
+                resolved_domains = sorted(resolved_domains)
+                if resolved_domains in cert_cache:
+                    cached_data = cert_cache[resolved_domains]
+                    if time.time() - cached_data['time'] <= max_age:
+                        logging.info('get cached cert: %s s old', time.time() - cached_data['time'])
+                        write_file(cert_file, cached_data['data'])
+                        logging.info('file written')
+                        continue
+                # no previous data or to old
+                logging.info('create new cert')
                 create_cert_data_standalone(resolved_domains)
-                create_haproxy_cert()
+                cert_data = create_haproxy_cert()
+                cert_cache[resolved_domains] = {
+                    'time': time.time(),
+                    'data': cert_data
+                }
+                write_file(cert_file, cert_data)
+                logging.info('file written')
+