diff --git a/core/src/main/java/org/nanohttpd/protocols/http/ServerRunnable.java b/core/src/main/java/org/nanohttpd/protocols/http/ServerRunnable.java
index b9907abb..0e2a4b5d 100644
--- a/core/src/main/java/org/nanohttpd/protocols/http/ServerRunnable.java
+++ b/core/src/main/java/org/nanohttpd/protocols/http/ServerRunnable.java
@@ -44,13 +44,13 @@
  */
 public class ServerRunnable implements Runnable {
 
-    private NanoHTTPD httpd;
+    private final NanoHTTPD httpd;
 
     private final int timeout;
 
-    private IOException bindException;
+    private volatile IOException bindException;
 
-    private boolean hasBinded = false;
+    private volatile boolean hasBinded = false;
 
     public ServerRunnable(NanoHTTPD httpd, int timeout) {
         this.httpd = httpd;