diff --git a/services/postfix-bounce-server.js b/services/postfix-bounce-server.js
index bc8bcede..60aba027 100644
--- a/services/postfix-bounce-server.js
+++ b/services/postfix-bounce-server.js
@@ -99,6 +99,9 @@ module.exports = callback => {
     });
 
     server.listen(config.postfixbounce.port, config.postfixbounce.host, () => {
+        if (started) {
+            return server.close();
+        }
         started = true;
         log.info('POSTFIXBOUNCE', 'Server listening on port %s', config.postfixbounce.port);
         setImmediate(callback);
diff --git a/services/verp-server.js b/services/verp-server.js
index 37bd17d1..d1fac80d 100644
--- a/services/verp-server.js
+++ b/services/verp-server.js
@@ -147,6 +147,9 @@ module.exports = callback => {
         }
         let host = hosts[pos++];
         server.listen(config.verp.port, host, () => {
+            if (started) {
+                return server.close();
+            }
             log.info('VERP', 'Server listening on %s:%s', host || '*', config.verp.port);
             setImmediate(startNextHost);
         });