diff --git a/omemo/file_crypto.py b/omemo/file_crypto.py
index 546af35..7dea01e 100644
--- a/omemo/file_crypto.py
+++ b/omemo/file_crypto.py
@@ -15,6 +15,7 @@
 # along with OMEMO Gajim Plugin. If not, see <http://www.gnu.org/licenses/>.
 
 import os
+import sys
 import hashlib
 import logging
 import socket
@@ -38,7 +39,7 @@ from gajim.gtk.dialogs import ErrorDialog, YesNoDialog
 from omemo.gtk.progress import ProgressWindow
 from omemo.backend.aes import aes_decrypt_file
 
-if os.name == 'nt':
+if sys.platform in ('win32', 'darwin'):
     import certifi
 
 log = logging.getLogger('gajim.plugin_system.omemo.filedecryption')
@@ -189,7 +190,7 @@ class Download:
                 get_request = urlopen(self.file.url, timeout=30, context=context)
             else:
                 cafile = None
-                if os.name == 'nt':
+                if sys.platform in ('win32', 'darwin'):
                     cafile = certifi.where()
                 context = ssl.create_default_context(cafile=cafile)
                 get_request = urlopen(self.file.url, timeout=30, context=context)
diff --git a/omemo/manifest.ini b/omemo/manifest.ini
index f4fe3bf..dfb1062 100644
--- a/omemo/manifest.ini
+++ b/omemo/manifest.ini
@@ -1,7 +1,7 @@
 [info]
 name: OMEMO
 short_name: omemo
-version: 2.6.40
+version: 2.6.41
 description: OMEMO is an XMPP Extension Protocol (XEP) for secure multi-client end-to-end encryption based on Axolotl and PEP. You need to install some dependencies, you can find install instructions for your system in the Github Wiki.
 authors: Bahtiar `kalkin-` Gadimov <bahtiar@gadimov.de>
  Daniel Gultsch <daniel@gultsch.de>