diff --git a/the_works/__init__.py b/the_works/__init__.py
index daea846..0a6eb31 100644
--- a/the_works/__init__.py
+++ b/the_works/__init__.py
@@ -50,8 +50,8 @@ def create_app(config=None):
 
 
 # helper function to print formatted file size; [source](https://stackoverflow.com/a/1094933)
-def sizeof_fmt(num: int, suffix: str = "B") -> str:
-  if type(num) == "String":
+def sizeof_fmt(num: int | str, suffix: str = "B") -> str:
+  if type(num) == str:
     num = int(num)
   for unit in ("", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi"):
     if abs(num) < 1024.0: