diff --git a/actions/imsettings.php b/actions/imsettings.php
index 0496aaacd5..d8fc8b87ca 100644
--- a/actions/imsettings.php
+++ b/actions/imsettings.php
@@ -62,19 +62,26 @@ class ImsettingsAction extends SettingsAction {
 
 	function handle_post() {
 
-		$jabber = jabber_normalize_jid($this->trimmed('jabber'));
+		$jabber = $this->trimmed('jabber');
 		$jabbernotify = $this->boolean('jabbernotify');
 		$updatefrompresence = $this->boolean('updatefrompresence');
 
-		if (!jabber_valid_base_jid($jabber)) {
-			$this->show_form(_('Not a valid Jabber ID'));
-			return;
-		} else if ($this->jabber_exists($jabber)) {
-			$this->show_form(_('Not a valid Jabber ID'));
-			return;
-		}
-
 		# Some validation
+		
+		if ($jabber) {
+			$jabber = jabber_normalize_jid($jabber);
+			if (!$jabber) {
+			    $this->show_form(_('Cannot normalize that Jabber ID'));
+			    return;
+			}
+			if (!jabber_valid_base_jid($jabber)) {
+			    $this->show_form(_('Not a valid Jabber ID'));
+			    return;
+		    } else if ($this->jabber_exists($jabber)) {
+			    $this->show_form(_('Jabber ID already belongs to another user.'));
+			    return;
+			}
+		}
 
 		$user = common_current_user();
 
diff --git a/lib/jabber.php b/lib/jabber.php
index e6529446b9..97d02544d6 100644
--- a/lib/jabber.php
+++ b/lib/jabber.php
@@ -27,11 +27,14 @@ function jabber_valid_base_jid($jid) {
 }
 
 function jabber_normalize_jid($jid) {
-	preg_match("/(?:([^\@]+)\@)?([^\/]+)(?:\/(.*))?$/", $jid, $matches);
-	$node = $matches[1];
-	$server = $matches[2];
-	$resource = $matches[3];
-	return strtolower($node.'@'.$server);
+	if (preg_match("/(?:([^\@]+)\@)?([^\/]+)(?:\/(.*))?$/", $jid, $matches)) {
+		$node = $matches[1];
+		$server = $matches[2];
+		$resource = $matches[3];
+		return strtolower($node.'@'.$server);
+	} else {
+		return NULL;
+	}
 }
 
 function jabber_connect($resource=NULL) {