diff --git a/wp-admin/admin.php b/wp-admin/admin.php
index 5b1ab37b6..3e8a6e493 100644
--- a/wp-admin/admin.php
+++ b/wp-admin/admin.php
@@ -120,6 +120,10 @@ if (isset($plugin_page)) {
 
 	include(ABSPATH . 'wp-admin/admin-footer.php');
 
+	// Make sure rules are flushed
+	global $wp_rewrite;
+	$wp_rewrite->flush_rules();
+
 	exit();
 } else {
 	do_action("load-$pagenow");
diff --git a/wp-includes/post.php b/wp-includes/post.php
index e4eb12bb1..71a2b1835 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -3112,8 +3112,11 @@ function _publish_post_hook($post_id) {
 function _save_post_hook($post_id, $post) {
 	if ( $post->post_type == 'page' ) {
 		clean_page_cache($post_id);
-		global $wp_rewrite;
-		$wp_rewrite->flush_rules();
+		// Avoid flushing rules for every post during import.
+		if ( !defined('WP_IMPORTING') ) {
+			global $wp_rewrite;
+			$wp_rewrite->flush_rules();
+		}
 	} else {
 		clean_post_cache($post_id);
 	}