diff --git a/src/globaleaks_eph_fs/__init__.py b/src/globaleaks_eph_fs/__init__.py
index fea3e1c..ee44fe9 100644
--- a/src/globaleaks_eph_fs/__init__.py
+++ b/src/globaleaks_eph_fs/__init__.py
@@ -46,6 +46,7 @@ def open(self, flags, mode=0o660):
         """
         with self.mutex:
             self.fd = os.open(self.filepath, os.O_RDWR | os.O_CREAT | os.O_APPEND, mode)
+            os.chmod(self.filepath, mode)
         return self
 
     def write(self, data):
diff --git a/tests/test.py b/tests/test.py
index 880e881..11358c2 100644
--- a/tests/test.py
+++ b/tests/test.py
@@ -167,20 +167,15 @@ def test_readdir(self):
     @patch("os.chmod")
     def test_chmod_success(self, mock_chmod):
         self.fs.create(TEST_PATH, 0o660)
-        self.fs.chmod(TEST_PATH, 0o644)
-        mock_chmod.assert_called_once_with(self.fs.files[TEST_PATH].filepath, 0o644)
+        mock_chmod.assert_called_with(self.fs.files[TEST_PATH].filepath, 0o660)
+        self.fs.chmod(TEST_PATH, 0o640)
+        mock_chmod.assert_called_with(self.fs.files[TEST_PATH].filepath, 0o640)
 
     def test_chmod_file_not_found(self):
         with self.assertRaises(FuseOSError) as context:
             self.fs.chmod("/nonexistent", 0o644)
         self.assertEqual(context.exception.errno, errno.ENOENT)
 
-    @patch("os.chmod", side_effect=PermissionError)
-    def test_chmod_permission_error(self, mock_chmod):
-        self.fs.create(TEST_PATH, 0o660)
-        with self.assertRaises(PermissionError):
-            self.fs.chmod(TEST_PATH, 0o644)
-
     @patch("os.chown")
     def test_chown_success(self, mock_chown):
         self.fs.create(TEST_PATH, 0o660)