diff --git a/src/__tests__/path_validation.spec.ts b/src/__tests__/path_validation.spec.ts
index 27853f5..960bbf3 100644
--- a/src/__tests__/path_validation.spec.ts
+++ b/src/__tests__/path_validation.spec.ts
@@ -9,13 +9,13 @@ const expectedManualIllegalChars: string[] = [
   "/",
   "\\",
   "?",
-  "%",
   "*",
   ":",
   "|",
   '"',
   "<",
   ">",
+  "\u0000",
 ];
 
 describe("replaceIllegalChars() removes all expected characters", () => {
diff --git a/src/util.ts b/src/util.ts
index 2b6bc84..49d1850 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -91,7 +91,7 @@ export const unicodeSlug = (str: string, savedAt: string) => {
 };
 
 export const replaceIllegalChars = (str: string): string => {
-  return str.replaceAll(ILLEGAL_CHAR_REGEX, REPLACEMENT_CHAR);
+  return str.replace(ILLEGAL_CHAR_REGEX, REPLACEMENT_CHAR);
 };
 
 export function formatDate(date: string, format: string): string {