diff --git a/frontend/src/ts/popups/custom-text-popup.ts b/frontend/src/ts/popups/custom-text-popup.ts
index 43bf0b0f4..c2c5816a0 100644
--- a/frontend/src/ts/popups/custom-text-popup.ts
+++ b/frontend/src/ts/popups/custom-text-popup.ts
@@ -237,8 +237,8 @@ function apply(): void {
   text = text.replace(/[\u200B-\u200D\u2060\uFEFF]/g, "");
 
   if ($(`${popup} .replaceControlCharacters input`).prop("checked")) {
-    text = text.replace(/(?<!\\)\\t/gm, "\t");
-    text = text.replace(/(?<!\\)\\n/gm, "\n");
+    text = text.replace(/([^\\]|^)\\t/gm, "$1\t");
+    text = text.replace(/([^\\]|^)\\n/gm, "$1\n");
     text = text.replace(/\\\\t/gm, "\\t");
     text = text.replace(/\\\\n/gm, "\\n");
   }