diff --git a/includes/core/um-actions-register.php b/includes/core/um-actions-register.php
index e9a6afc0..9081cf43 100644
--- a/includes/core/um-actions-register.php
+++ b/includes/core/um-actions-register.php
@@ -350,7 +350,8 @@ function um_submit_form_register( $args ) {
 
 	$unique_userID = uniqid();
 
-	if ( empty( $user_login ) || strlen( $user_login ) > 30 && ! is_email( $user_login ) ) {
+	// see dbDelta and WP native DB structure user_login varchar(60)
+	if ( empty( $user_login ) || mb_strlen( $user_login ) > 60 && ! is_email( $user_login ) ) {
 		$user_login = 'user' . $unique_userID;
 		while ( username_exists( $user_login ) ) {
 			$unique_userID = uniqid();
diff --git a/includes/um-short-functions.php b/includes/um-short-functions.php
index 092a21b9..416137c6 100644
--- a/includes/um-short-functions.php
+++ b/includes/um-short-functions.php
@@ -14,7 +14,7 @@
  * @return string
  */
 function um_trim_string( $s, $length = 20 ) {
-	$s = strlen( $s ) > $length ? substr( $s, 0, $length ) . "..." : $s;
+	$s = mb_strlen( $s ) > $length ? substr( $s, 0, $length ) . "..." : $s;
 
 	return $s;
 }