diff --git a/whispercpp.pyx b/whispercpp.pyx
index 27855c1..2f853bc 100644
--- a/whispercpp.pyx
+++ b/whispercpp.pyx
@@ -86,7 +86,7 @@ cdef class Whisper:
     cdef whisper_full_params params
 
     def __init__(self, model=DEFAULT_MODEL, pb=None):
-        model_fullname = f'ggml-{model}.bin'
+        model_fullname = f'ggml-{model}.bin'.encode('utf8')
         download_model(model_fullname)
         model_path = Path(MODELS_DIR).joinpath(model_fullname)
         cdef bytes model_b = str(model_path).encode('utf8')