diff --git a/src/wireviz/svgembed.py b/src/wireviz/svgembed.py
index 3226c8d..0999b8f 100644
--- a/src/wireviz/svgembed.py
+++ b/src/wireviz/svgembed.py
@@ -4,13 +4,15 @@
 import re
 import base64
 from pathlib import Path
+import os
 
-def embed_svg_images(fn):
-    fn = Path(fn).resolve()
+def embed_svg_images(filename_in: Path, overwrite: bool = True):
+    filename_in = Path(filename_in).resolve()
+    filename_out = f'{filename_in.with_suffix("")}.b64.svg'
     images_b64 = {}  # cache base-64 encoded images
     num_images = 0   # just for debugging
     re_xlink=re.compile(r"xlink:href=\"(?P<URL>.*?)\"", re.IGNORECASE)
-    with open(fn) as file_in, open(f'{fn.with_suffix("")}.b64.svg','w') as file_out:
+    with open(filename_in) as file_in, open(filename_out,'w') as file_out:
         for line in file_in:
             for xlink in re_xlink.finditer(line):
                 num_images = num_images + 1
@@ -19,7 +21,7 @@ def embed_svg_images(fn):
                 if not imgurl in images_b64:
                     print('  ✅This URL is new')
                     if not Path(imgurl).is_absolute():  # resolve relative image path
-                        imgurl_abs = (Path(fn).parent / imgurl).resolve()
+                        imgurl_abs = (Path(filename_in).parent / imgurl).resolve()
                         print(imgurl, '-->', imgurl_abs)
                     else:
                         imgurl_abs = imgurl
@@ -34,6 +36,10 @@ def embed_svg_images(fn):
                                     f'data:image/png;base64, {images_b64[imgurl]}')
             file_out.write(line)
 
+        if overwrite:
+            os.remove(filename_in)
+            os.rename(filename_out, filename_in)
+
     print(f'Embedded {num_images} instances of {len(images_b64)} different images.')
     print()