diff --git a/src/wp-includes/wp-db.php b/src/wp-includes/wp-db.php
index 2e392d0954..9761de99a8 100644
--- a/src/wp-includes/wp-db.php
+++ b/src/wp-includes/wp-db.php
@@ -1159,6 +1159,10 @@ class wpdb {
 	 * @return string Escaped string.
 	 */
 	function _real_escape( $string ) {
+		if ( ! is_scalar( $string ) && ! is_null( $string ) ) {
+			return '';
+		}
+
 		if ( $this->dbh ) {
 			if ( $this->use_mysqli ) {
 				$escaped = mysqli_real_escape_string( $this->dbh, $string );