diff --git a/controle_cotisation/main.py b/controle_cotisation/main.py
index cd71cf2..3f8409b 100755
--- a/controle_cotisation/main.py
+++ b/controle_cotisation/main.py
@@ -105,7 +105,7 @@ def sendmail_with_attachment(headers, data, attachment_header, attachment, endin
     msg = bytes(headers + "\n", 'utf-8') \
         + quopri.encodestring(bytes(data, 'utf-8')) \
         + bytes(attachment_header + "\n", 'utf-8') \
-        + bytes(attachment, 'base64') \
+        + base64(attachment) \
         + bytes(ending + "\n", 'utf-8')
 
     subprocess.run([SENDMAIL_LOCATION, "-t", "-oi"], input=msg)