diff --git a/src/wp-includes/theme.php b/src/wp-includes/theme.php
index 5fa7a23146..b707990dcf 100644
--- a/src/wp-includes/theme.php
+++ b/src/wp-includes/theme.php
@@ -2517,6 +2517,9 @@ function add_theme_support( $feature, ...$args ) {
 				unset( $post_formats['standard'] );
 
 				$args[0] = array_intersect( $args[0], array_keys( $post_formats ) );
+			} else {
+				_doing_it_wrong( "add_theme_support( 'post-formats' )", __( 'You need to pass an array of types.' ), '5.6.0' );
+				return false;
 			}
 			break;