diff --git a/audiblez/core.py b/audiblez/core.py
index 882aa9b..3953d4b 100755
--- a/audiblez/core.py
+++ b/audiblez/core.py
@@ -298,7 +298,7 @@ def concat_wavs_with_ffmpeg(chapter_files, output_folder, filename):
         for wav_file in chapter_files:
             f.write(f"file '{wav_file}'\n")
     concat_file_path = Path(output_folder) / filename.replace('.epub', '.tmp.mp4')
-    subprocess.run(['ffmpeg', '-y', '-f', 'concat', '-i', wav_list_txt, '-c', 'copy', concat_file_path])
+    subprocess.run(['ffmpeg', '-y', '-f', 'concat', '-safe', '0', '-i', wav_list_txt, '-c', 'copy', concat_file_path])
     Path(wav_list_txt).unlink()
     return concat_file_path
 
diff --git a/pyproject.toml b/pyproject.toml
index 6654791..d47e29c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "audiblez"
-version = "0.4.8"
+version = "0.4.9"
 description = "Generate audiobooks from e-books (epub to wav/m4b)"
 authors = [
     { name = "Claudio Santini", email = "hireclaudio@gmail.com" }
diff --git a/test/test_main.py b/test/test_main.py
index 634eba1..a814fde 100644
--- a/test/test_main.py
+++ b/test/test_main.py
@@ -33,10 +33,10 @@ class MainTest(unittest.TestCase):
         url = 'https://archive.org/download/AnimalFarmByGeorgeOrwell/Animal%20Farm%20by%20George%20Orwell.epub'
         self.base('orwell', url)
 
-    def test_italian_pirandello(self):
+    def test_italian_pirandello_and_filename_with_spaces(self):
         url = 'https://www.liberliber.eu/mediateca/libri/p/pirandello/cosi_e_se_vi_pare_1925/epub/pirandello_cosi_e_se_vi_pare_1925.epub'
-        self.base('pirandello', url, voice='im_nicola')
-        self.assertTrue(Path('pirandello.m4b').exists())
+        self.base('pirandello e spazio', url, voice='im_nicola')
+        self.assertTrue(Path('pirandello e spazio.m4b').exists())
 
     def test_italian_manzoni(self):
         url = 'https://www.liberliber.eu/mediateca/libri/m/manzoni/i_promessi_sposi/epub/manzoni_i_promessi_sposi.epub'