diff --git a/packages/playground/remote/src/lib/playground-mu-plugin/playground-includes/wp_http_fetch.php b/packages/playground/remote/src/lib/playground-mu-plugin/playground-includes/wp_http_fetch.php
index 6c2131d8e6..ecdaf90b33 100644
--- a/packages/playground/remote/src/lib/playground-mu-plugin/playground-includes/wp_http_fetch.php
+++ b/packages/playground/remote/src/lib/playground-mu-plugin/playground-includes/wp_http_fetch.php
@@ -110,7 +110,7 @@ protected static function format_get($url, $data)
 			} else {
 				$query = $url_parts['query'];
 			}
-			$query .= '&' . http_build_query($data, null, '&');
+			$query .= '&' . http_build_query($data, '', '&');
 			$query = trim($query, '&');
 			if (empty($url_parts['query'])) {
 				$url .= '?' . $query;