diff --git a/examples/arithmetics.pegjs b/examples/arithmetics.pegjs
index 52fae2a..a0b7bc0 100644
--- a/examples/arithmetics.pegjs
+++ b/examples/arithmetics.pegjs
@@ -19,4 +19,4 @@ primary
   / "(" additive:additive ")" { return additive; }
 
 integer "integer"
-  = digits:[0-9]+ { return parseInt(digits.join(""), 10); }
+  = digits:$[0-9]+ { return parseInt(digits, 10); }