diff --git a/core/src/main/java/com/muwire/core/Constants.java b/core/src/main/java/com/muwire/core/Constants.java
index 4c1ce2ad..900040fd 100644
--- a/core/src/main/java/com/muwire/core/Constants.java
+++ b/core/src/main/java/com/muwire/core/Constants.java
@@ -5,6 +5,7 @@ import net.i2p.crypto.SigType;
 public class Constants {
     public static final byte PERSONA_VERSION = (byte)1;
     public static final String INVALID_NICKNAME_CHARS = "'\"();<>=@$%";
+    public static final int MAX_NICKNAME_LENGTH = 30;
     public static final byte FILE_CERT_VERSION = (byte)2;
     public static final int CHAT_VERSION = 1;
     
diff --git a/core/src/main/java/com/muwire/core/util/DataUtil.java b/core/src/main/java/com/muwire/core/util/DataUtil.java
index bdd2a77b..baab322d 100644
--- a/core/src/main/java/com/muwire/core/util/DataUtil.java
+++ b/core/src/main/java/com/muwire/core/util/DataUtil.java
@@ -218,6 +218,8 @@ public class DataUtil {
     }
     
     public static boolean isValidName(String name) {
+        if (name.length() > Constants.MAX_NICKNAME_LENGTH)
+            return false;
         for (int i = 0; i < Constants.INVALID_NICKNAME_CHARS.length(); i++)
             if (name.indexOf(Constants.INVALID_NICKNAME_CHARS.charAt(i)) >= 0)
                 return false;
diff --git a/gui/griffon-app/lifecycle/Ready.groovy b/gui/griffon-app/lifecycle/Ready.groovy
index 90130fa8..e31d2953 100644
--- a/gui/griffon-app/lifecycle/Ready.groovy
+++ b/gui/griffon-app/lifecycle/Ready.groovy
@@ -119,7 +119,8 @@ class Ready extends AbstractLifecycleHandler {
                 continue
             }
             if (!DataUtil.isValidName(nickname)) {
-                JOptionPane.showMessageDialog(null, "Nickname cannot contain any of ${Constants.INVALID_NICKNAME_CHARS} choose another",
+                JOptionPane.showMessageDialog(null, 
+                    "Nickname cannot contain any of ${Constants.INVALID_NICKNAME_CHARS} and must be no longer than ${Constants.MAX_NICKNAME_LENGTH} characters.  Choose another.",
                         "Select another nickname", JOptionPane.WARNING_MESSAGE)
                 continue
             }
diff --git a/webui/src/main/java/com/muwire/webui/InitServlet.java b/webui/src/main/java/com/muwire/webui/InitServlet.java
index adc10eb7..8853e50a 100644
--- a/webui/src/main/java/com/muwire/webui/InitServlet.java
+++ b/webui/src/main/java/com/muwire/webui/InitServlet.java
@@ -21,7 +21,8 @@ public class InitServlet extends HttpServlet {
                 throw new Exception("Nickname cannot be blank");
             
             if (!DataUtil.isValidName(nickname))
-                throw new Exception("Nickname cannot contain any of " + Constants.INVALID_NICKNAME_CHARS);
+                throw new Exception("Nickname cannot contain any of " + Constants.INVALID_NICKNAME_CHARS +
+                        " and must be no longer than " + Constants.MAX_NICKNAME_LENGTH + " characters.");
             
             String downloadLocation = req.getParameter("download_location");
             if (downloadLocation == null)