diff --git a/wp-activate.php b/wp-activate.php
index 22d69acf60..a796cc5e48 100644
--- a/wp-activate.php
+++ b/wp-activate.php
@@ -105,7 +105,7 @@ get_header();
 			    echo '<p>'.$result->get_error_message().'</p>';
 			}
 		} else {
-			$url = get_blogaddress_by_id( (int) $result['blog_id'] );
+			$url = isset( $result['blog_id'] ) ? get_blogaddress_by_id( (int) $result['blog_id'] ) : '';
 			$user = get_userdata( (int) $result['user_id'] );
 			?>
 			<h2><?php _e('Your account is now active!'); ?></h2>
@@ -115,7 +115,7 @@ get_header();
 				<p><span class="h3"><?php _e('Password:'); ?></span> <?php echo $result['password']; ?></p>
 			</div>
 
-			<?php if ( $url != network_home_url('', 'http') ) : ?>
+			<?php if ( $url && $url != network_home_url( '', 'http' ) ) : ?>
 				<p class="view"><?php printf( __('Your account is now activated. <a href="%1$s">View your site</a> or <a href="%2$s">Log in</a>'), $url, $url . 'wp-login.php' ); ?></p>
 			<?php else: ?>
 				<p class="view"><?php printf( __('Your account is now activated. <a href="%1$s">Log in</a> or go back to the <a href="%2$s">homepage</a>.' ), network_site_url('wp-login.php', 'login'), network_home_url() ); ?></p>