diff --git a/lib/pipeline/server.js b/lib/pipeline/server.js
index 172cbde9d..99c824ac9 100644
--- a/lib/pipeline/server.js
+++ b/lib/pipeline/server.js
@@ -12,6 +12,13 @@ class Server {
   }
 
   start(callback) {
+    if (this.server && this.server.listening) {
+      this.logger.warn("a webserver is already running at " + ("http://" + this.hostname + ":" + this.port).bold.underline.green);
+      if (callback) {
+        callback();
+      }
+      return;
+    }
     let serve = serveStatic(this.dist, {'index': ['index.html', 'index.htm']});
 
     this.server = http.createServer(function onRequest(req, res) {
@@ -26,6 +33,13 @@ class Server {
   }
 
   stop(callback) {
+    if (!this.server || !this.server.listening) {
+      this.logger.warn("no webserver is currently running");
+      if (callback) {
+        callback();
+      }
+      return;
+    }
     this.server.shutdown(function() {
       if (callback) {
         callback();