diff --git a/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleSocket.java b/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleSocket.java
index 55713acf2..2aa8da52a 100644
--- a/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleSocket.java
+++ b/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleSocket.java
@@ -76,4 +76,12 @@ public interface GuacamoleSocket {
      */
     public void close() throws GuacamoleException;
 
+    /**
+     * Returns whether this GuacamoleSocket is open and can be used for reading
+     * and writing.
+     * 
+     * @return true if this GuacamoleSocket is open, false otherwise.
+     */
+    public boolean isOpen();
+
 }
diff --git a/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleTunnel.java b/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleTunnel.java
index cb1020cd7..4a7bc0fd5 100644
--- a/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleTunnel.java
+++ b/guacamole-common/src/main/java/net/sourceforge/guacamole/net/GuacamoleTunnel.java
@@ -57,6 +57,8 @@ public class GuacamoleTunnel {
     private ReentrantLock readerLock;
     private ReentrantLock writerLock;
 
+    private boolean open = true;
+
     /**
      * Creates a new GuacamoleTunnel which synchronizes access to the
      * Guacamole instruction stream associated with the given GuacamoleSocket.
@@ -146,6 +148,16 @@ public class GuacamoleTunnel {
         return uuid;
     }
 
+    /**
+     * Returns the GuacamoleSocket used by this GuacamoleTunnel for reading
+     * and writing.
+     * 
+     * @return The GuacamoleSocket used by this GuacamoleTunnel.
+     */
+    public GuacamoleSocket getSocket() {
+        return socket;
+    }
+
     /**
      * Release all resources allocated to this GuacamoleTunnel.
      * 
@@ -156,4 +168,13 @@ public class GuacamoleTunnel {
         socket.close();
     }
 
+    /**
+     * Returns whether this GuacamoleTunnel is open, or has been closed.
+     * 
+     * @return true if this GuacamoleTunnel is open, false if it is closed.
+     */
+    public boolean isOpen() {
+        return socket.isOpen();
+    }
+    
 }
diff --git a/guacamole-common/src/main/java/net/sourceforge/guacamole/net/InetGuacamoleSocket.java b/guacamole-common/src/main/java/net/sourceforge/guacamole/net/InetGuacamoleSocket.java
index cd5783023..9a0e19893 100644
--- a/guacamole-common/src/main/java/net/sourceforge/guacamole/net/InetGuacamoleSocket.java
+++ b/guacamole-common/src/main/java/net/sourceforge/guacamole/net/InetGuacamoleSocket.java
@@ -132,5 +132,10 @@ public class InetGuacamoleSocket implements GuacamoleSocket {
         return writer;
     }
 
+    @Override
+    public boolean isOpen() {
+        return !sock.isClosed();
+    }
+    
 
 }
diff --git a/guacamole-common/src/main/java/net/sourceforge/guacamole/protocol/ConfiguredGuacamoleSocket.java b/guacamole-common/src/main/java/net/sourceforge/guacamole/protocol/ConfiguredGuacamoleSocket.java
index a3de88cd7..192c32ca2 100644
--- a/guacamole-common/src/main/java/net/sourceforge/guacamole/protocol/ConfiguredGuacamoleSocket.java
+++ b/guacamole-common/src/main/java/net/sourceforge/guacamole/protocol/ConfiguredGuacamoleSocket.java
@@ -121,4 +121,9 @@ public class ConfiguredGuacamoleSocket implements GuacamoleSocket {
         socket.close();
     }
 
+    @Override
+    public boolean isOpen() {
+        return socket.isOpen();
+    }
+
 }
diff --git a/guacamole-common/src/main/java/net/sourceforge/guacamole/servlet/GuacamoleHTTPTunnelServlet.java b/guacamole-common/src/main/java/net/sourceforge/guacamole/servlet/GuacamoleHTTPTunnelServlet.java
index 90d91ab60..e652f154d 100644
--- a/guacamole-common/src/main/java/net/sourceforge/guacamole/servlet/GuacamoleHTTPTunnelServlet.java
+++ b/guacamole-common/src/main/java/net/sourceforge/guacamole/servlet/GuacamoleHTTPTunnelServlet.java
@@ -227,10 +227,15 @@ public abstract class GuacamoleHTTPTunnelServlet extends HttpServlet {
         HttpSession httpSession = request.getSession(false);
         GuacamoleSession session = new GuacamoleSession(httpSession);
 
+        // Get tunnel, ensure tunnel exists
         GuacamoleTunnel tunnel = session.getTunnel(tunnelUUID);
         if (tunnel == null)
             throw new GuacamoleResourceNotFoundException("No such tunnel.");
 
+        // Ensure tunnel is open
+        if (!tunnel.isOpen())
+            throw new GuacamoleResourceNotFoundException("Tunnel is closed.");
+        
         // Obtain exclusive read access
         GuacamoleReader reader = tunnel.acquireReader();
 
@@ -265,7 +270,7 @@ public abstract class GuacamoleHTTPTunnelServlet extends HttpServlet {
                 if (tunnel.hasQueuedReaderThreads())
                     break;
 
-            } while ((message = reader.read()) != null);
+            } while (tunnel.isOpen() && (message = reader.read()) != null);
 
             // Close tunnel immediately upon EOF
             if (message == null)
@@ -340,7 +345,8 @@ public abstract class GuacamoleHTTPTunnelServlet extends HttpServlet {
             char[] buffer = new char[8192];
 
             int length;
-            while ((length = input.read(buffer, 0, buffer.length)) != -1)
+            while (tunnel.isOpen() && 
+                    (length = input.read(buffer, 0, buffer.length)) != -1)
                 writer.write(buffer, 0, length);
 
         }