diff --git a/lib/repl/repl-search.js b/lib/repl/repl-search.js
index 84885f65a..00fd7d42f 100644
--- a/lib/repl/repl-search.js
+++ b/lib/repl/repl-search.js
@@ -47,7 +47,8 @@ function isCtrlR(k) {
 }
 
 function isControlChar(c) {
-  return /[\x00-\x1F]/.test(c);
+  const code = c.charCodeAt(0);
+  return code >= 0 && code <= 31;
 }
 
 function search(query, repl, next) {