diff --git a/src/prelude/string.ts b/src/prelude/string.ts
index c2ad8a2e79..b907e0a2e1 100644
--- a/src/prelude/string.ts
+++ b/src/prelude/string.ts
@@ -1,5 +1,5 @@
 export function concat(xs: string[]): string {
-	return xs.reduce((a, b) => a + b, '');
+	return xs.join('');
 }
 
 export function capitalize(s: string): string {