diff --git a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationFailureListener.java b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationFailureListener.java
index c110144c6..0a2ec03b3 100644
--- a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationFailureListener.java
+++ b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationFailureListener.java
@@ -1,5 +1,6 @@
 package net.sourceforge.guacamole.net.event.listener;
 
+import net.sourceforge.guacamole.GuacamoleException;
 import net.sourceforge.guacamole.net.event.AuthenticationFailureEvent;
 
 /**
@@ -17,7 +18,12 @@ public interface AuthenticationFailureListener  {
      * 
      * @param e The AuthenticationFailureEvent describing the authentication
      *          failure that just occurred.
+     * @throws GuacamoleException If an error occurs while handling the
+     *                            authentication failure event. Note that
+     *                            throwing an exception will NOT cause the
+     *                            authentication failure to be canceled.
      */
-    public void authenticationFailed(AuthenticationFailureEvent e);
+    public void authenticationFailed(AuthenticationFailureEvent e)
+            throws GuacamoleException;
     
 }
diff --git a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationSuccessListener.java b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationSuccessListener.java
index f7fea9d56..5422816c8 100644
--- a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationSuccessListener.java
+++ b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/AuthenticationSuccessListener.java
@@ -1,5 +1,6 @@
 package net.sourceforge.guacamole.net.event.listener;
 
+import net.sourceforge.guacamole.GuacamoleException;
 import net.sourceforge.guacamole.net.event.AuthenticationSuccessEvent;
 
 /**
@@ -22,7 +23,12 @@ public interface AuthenticationSuccessListener {
      * @return true if the successful authentication attempt should be
      *         allowed, or false if the attempt should be denied, causing
      *         the attempt to effectively fail.
+     * @throws GuacamoleException If an error occurs while handling the
+     *                            authentication success event. Throwing an
+     *                            exception will also cancel the authentication
+     *                            success.
      */
-    public boolean authenticationSucceeded(AuthenticationSuccessEvent e);
+    public boolean authenticationSucceeded(AuthenticationSuccessEvent e)
+            throws GuacamoleException;
 
 }
diff --git a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelAttachListener.java b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelAttachListener.java
index 7936faef3..e8e6dc7af 100644
--- a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelAttachListener.java
+++ b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelAttachListener.java
@@ -1,5 +1,6 @@
 package net.sourceforge.guacamole.net.event.listener;
 
+import net.sourceforge.guacamole.GuacamoleException;
 import net.sourceforge.guacamole.net.event.TunnelAttachEvent;
 
 /**
@@ -20,7 +21,11 @@ public interface TunnelAttachListener {
      * @return true if the tunnel should be allowed to be attached, or false
      *         if the attempt should be denied, causing the attempt to
      *         effectively fail.
+     * @throws GuacamoleException If an error occurs while handling the
+     *                            tunnel attach event. Throwing an exception
+     *                            will also stop the tunnel from being attached.
      */
-    public boolean tunnelAttached(TunnelAttachEvent e);
+    public boolean tunnelAttached(TunnelAttachEvent e)
+            throws GuacamoleException;
 
 }
diff --git a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelDetachListener.java b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelDetachListener.java
index 9eea91f50..cc7a84d35 100644
--- a/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelDetachListener.java
+++ b/guacamole-ext/src/main/java/net/sourceforge/guacamole/net/event/listener/TunnelDetachListener.java
@@ -1,5 +1,6 @@
 package net.sourceforge.guacamole.net.event.listener;
 
+import net.sourceforge.guacamole.GuacamoleException;
 import net.sourceforge.guacamole.net.event.TunnelDetachEvent;
 
 /**
@@ -20,7 +21,11 @@ public interface TunnelDetachListener {
      * @return true if the tunnel should be allowed to be detached, or false
      *         if the attempt should be denied, causing the attempt to
      *         effectively fail.
+     * @throws GuacamoleException If an error occurs while handling the
+     *                            tunnel detach event. Throwing an exception
+     *                            will also stop the tunnel from being detached.
      */
-    public boolean tunnelDetached(TunnelDetachEvent e);
+    public boolean tunnelDetached(TunnelDetachEvent e)
+            throws GuacamoleException;
 
 }