diff --git wp-admin/css/wp-admin.dev.css wp-admin/css/wp-admin.dev.css
index 0a70bd5..c07d355 100644
--- wp-admin/css/wp-admin.dev.css
+++ wp-admin/css/wp-admin.dev.css
@@ -2651,6 +2651,10 @@ ul.add-menu-item-tabs li {
 	width: 95%;
 }
 
+.form-field .site-address {
+	width:auto;
+}
+
 p.description,
 .form-wrap p {
 	margin: 2px 0 5px;
diff --git wp-admin/network/site-new.php wp-admin/network/site-new.php
index a94aaf3..d808908 100644
--- wp-admin/network/site-new.php
+++ wp-admin/network/site-new.php
@@ -117,9 +117,9 @@ if ( ! empty( $messages ) ) {
 			<th scope="row"><?php _e( 'Site Address' ) ?></th>
 			<td>
 			<?php if ( is_subdomain_install() ) { ?>
-				<input name="blog[domain]" type="text" class="regular-text" title="<?php _e( 'Domain' ) ?>"/>.<?php echo preg_replace( '|^www\.|', '', $current_site->domain );?>
+				<input name="blog[domain]" type="text" class="site-address regular-text" title="<?php _e( 'Domain' ) ?>"/>.<?php echo preg_replace( '|^www\.|', '', $current_site->domain );?>
 			<?php } else {
-				echo $current_site->domain . $current_site->path ?><input name="blog[domain]" class="regular-text" type="text" title="<?php _e( 'Domain' ) ?>"/>
+				echo $current_site->domain . $current_site->path ?><input name="blog[domain]" class="site-address regular-text" type="text" title="<?php _e( 'Domain' ) ?>"/>
 			<?php }
 			echo '<p>' . __( 'Only the characters a-z and 0-9 recommended.' ) . '</p>';
 			?>