diff --git a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
index 3855b0995..d446b78b3 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
@@ -532,7 +532,8 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
 
     @Override
     public final boolean isAnonymous() {
-        return config.getUsername() == null && usedUsername == null;
+        return config.getUsername() == null && usedUsername == null
+                        && !config.allowNullOrEmptyUsername;
     }
 
     private String serviceName;
diff --git a/smack-sasl-provided/src/main/java/org/jivesoftware/smack/sasl/provided/SASLExternalMechanism.java b/smack-sasl-provided/src/main/java/org/jivesoftware/smack/sasl/provided/SASLExternalMechanism.java
index 1bfd92494..d8997789b 100644
--- a/smack-sasl-provided/src/main/java/org/jivesoftware/smack/sasl/provided/SASLExternalMechanism.java
+++ b/smack-sasl-provided/src/main/java/org/jivesoftware/smack/sasl/provided/SASLExternalMechanism.java
@@ -34,7 +34,8 @@ public class SASLExternalMechanism extends SASLMechanism {
 
     @Override
     protected void authenticateInternal(CallbackHandler cbh) throws SmackException {
-        throw new UnsupportedOperationException("CallbackHandler not (yet) supported");
+        // Do nothing. Auth will be done external to Smack and which will receive the localpart
+        // after the resource binding
     }
 
     @Override