diff --git a/lib/serializer.js b/lib/serializer.js
index 1e6a8eaf..387e8927 100644
--- a/lib/serializer.js
+++ b/lib/serializer.js
@@ -101,7 +101,8 @@ module.exports = class Serializer {
   asString (str) {
     if (str.length < 42) {
       return this.asStringSmall(str)
-    } else if (STR_ESCAPE.test(str) === false) {
+    } else if (str.length < 5000 && STR_ESCAPE.test(str) === false) {
+      // Only use the regular expression for shorter input. The overhead is otherwise too much.
       return '"' + str + '"'
     } else {
       return JSON.stringify(str)