diff --git a/wp-includes/post.php b/wp-includes/post.php
index 5c61c6d713..b7457217e7 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -2281,14 +2281,14 @@ function wp_insert_attachment($object, $file = false, $parent = 0) {
 		$post_name = sanitize_title($post_name);
 
 	// expected_slashed ($post_name)
-	$post_name_check = $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM $wpdb->posts WHERE post_name = '$post_name' AND post_status = 'inherit' AND ID != %d LIMIT 1", $post_ID));
+	$post_name_check = $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_status = 'inherit' AND ID != %d LIMIT 1", $post_name, $post_ID));
 
 	if ($post_name_check) {
 		$suffix = 2;
 		while ($post_name_check) {
 			$alt_post_name = $post_name . "-$suffix";
 			// expected_slashed ($alt_post_name, $post_name)
-			$post_name_check = $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM $wpdb->posts WHERE post_name = '$alt_post_name' AND post_status = 'inherit' AND ID != %d AND post_parent = %d LIMIT 1", $post_ID, $post_parent));
+			$post_name_check = $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_status = 'inherit' AND ID != %d AND post_parent = %d LIMIT 1", $alt_post_name, $post_ID, $post_parent));
 			$suffix++;
 		}
 		$post_name = $alt_post_name;