diff --git a/src/wireviz/svgembed.py b/src/wireviz/svgembed.py
index 69961dd..ea802ca 100644
--- a/src/wireviz/svgembed.py
+++ b/src/wireviz/svgembed.py
@@ -4,6 +4,7 @@
 import re
 import base64
 from pathlib import Path
+from typing import Union
 
 mime_subtype_replacements = {'jpg': 'jpeg', 'tif': 'tiff'}
 
@@ -25,15 +26,15 @@ def embed_svg_images(svg_in: str, base_path: Path):
     return svg_out
 
 
-def get_mime_subtype(filename: Path):
-    mime_subtype = filename.suffix.lstrip('.').lower()
+def get_mime_subtype(filename: Union[str, Path]):
+    mime_subtype = Path(filename).suffix.lstrip('.').lower()
     if mime_subtype in mime_subtype_replacements:
         mime_subtype = mime_subtype_replacements[mime_subtype]
     return mime_subtype
 
 
-def embed_svg_images_file(filename_in: Path, overwrite: bool = True):
-    filename_in = filename_in.resolve()
+def embed_svg_images_file(filename_in: Union[str, Path], overwrite: bool = True):
+    filename_in = Path(filename_in).resolve()
     filename_out = filename_in.with_suffix('.b64.svg')
     filename_out.write_text(embed_svg_images(filename_in.read_text(), filename_in.parent))
     if overwrite: