diff --git a/biseau/core.py b/biseau/core.py
index 427bf2aaba36d153a0e91fe8755e8e247e36bc7b..4b4a16fd81cf55d502d62d673dad5d5771b02a05 100644
--- a/biseau/core.py
+++ b/biseau/core.py
@@ -32,13 +32,13 @@ def single_image_from_filenames(fnames:[str], outfile:str=None, dotfile:str=None
     return compile_to_single_image(final_context, outfile=outfile, dotfile=dotfile, return_image=return_image, verbosity=verbosity)
 
 
-def gif_from_filenames(fnames:[str], giffile:str=None, dotfile_template:str=None, duration:int=1000, verbosity:int=0) -> bytes or str:
+def gif_from_filenames(fnames:[str], giffile:str=None, dotfile_template:str=None, duration:int=1000, loop:int=0, verbosity:int=0) -> bytes or str:
     """Make a gif, with each ASP model as an image. Save it in outfile and dotfile_template"""
     pipeline = build_pipeline(fnames, verbosity)
     final_context = run(pipeline, verbosity=verbosity)
     first, *lasts = compile_to_images(final_context, dotfile_template=dotfile_template, return_image=True, verbosity=verbosity)
     output = io.BytesIO() if giffile is None else giffile
-    first.save(output, save_all=True, append_images=lasts, duration=duration, loop=0)
+    first.save(output, format='gif', append_images=lasts, duration=duration, loop=loop, save_all=True)
     return output.getvalue() if giffile is None else giffile