diff --git a/projects/packages/search/src/instant-search/lib/api.js b/projects/packages/search/src/instant-search/lib/api.js
index caedd2ab84bf6..678b25d1733a8 100644
--- a/projects/packages/search/src/instant-search/lib/api.js
+++ b/projects/packages/search/src/instant-search/lib/api.js
@@ -263,7 +263,7 @@ function generateApiQueryString( {
 	isInCustomizer = false,
 	additionalBlogIds = [],
 	highlightFields = [ 'title', 'content', 'comments' ],
-	customResults = {},
+	customResults = [],
 } ) {
 	if ( query === null ) {
 		query = '';