diff --git a/playgrounds/sandbox/run.js b/playgrounds/sandbox/run.js
index 3a62286b24..dd66b2e184 100644
--- a/playgrounds/sandbox/run.js
+++ b/playgrounds/sandbox/run.js
@@ -85,9 +85,25 @@ for (const generate of /** @type {const} */ (['client', 'server'])) {
 		}
 
 		write(output_js, compiled.js.code + '\n//# sourceMappingURL=' + path.basename(output_map));
-
 		write(output_map, compiled.js.map.toString());
 
+		// generate with templatingMode: 'functional'
+		if (generate === 'client') {
+			const compiled = compile(source, {
+				dev: true,
+				filename: input,
+				generate,
+				runes: argv.values.runes,
+				templatingMode: 'functional'
+			});
+
+			const output_js = `${cwd}/output/${generate}/${file}.functional.js`;
+			const output_map = `${cwd}/output/${generate}/${file}.functional.js.map`;
+
+			write(output_js, compiled.js.code + '\n//# sourceMappingURL=' + path.basename(output_map));
+			write(output_map, compiled.js.map.toString());
+		}
+
 		if (compiled.css) {
 			write(output_css, compiled.css.code);
 		}