diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index cd84a19f6c..e0e01299a0 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -3225,6 +3225,10 @@ function _wp_theme_json_webfonts_handler() {
 		return;
 	}
 
+	if ( ! wp_theme_has_theme_json() ) {
+		return;
+	}
+
 	// Webfonts to be processed.
 	$registered_webfonts = array();