diff --git a/src/wp-includes/http.php b/src/wp-includes/http.php
index 9bb554a0e6..05792c29c2 100644
--- a/src/wp-includes/http.php
+++ b/src/wp-includes/http.php
@@ -523,7 +523,11 @@ function wp_http_validate_url( $url ) {
 
 	$parsed_home = @parse_url( get_option( 'home' ) );
 
-	$same_host = strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] );
+	if ( isset( $parsed_home['host'] ) ) { 
+		$same_host = ( strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] ) || 'localhost' === strtolower( $parsed_url['host'] ) );
+	} else {
+		$same_host = false;
+	}
 
 	if ( ! $same_host ) {
 		$host = trim( $parsed_url['host'], '.' );