diff --git a/trollmoves/server.py b/trollmoves/server.py
index 332401a8..2d65a21b 100644
--- a/trollmoves/server.py
+++ b/trollmoves/server.py
@@ -129,12 +129,12 @@ def pong(self, message):
     def push(self, message):
         """Reply to push request."""
         new_msg = self._move_files(message)
-        if new_msg and new_msg.type is not 'err':
+        if new_msg and new_msg.type != 'err':
             _destination = clean_url(new_msg.data['destination'])
             new_msg = Message(message.subject,
                               _get_push_message_type(message),
                               data=message.data.copy())
-            new_msg.data['destination'] = _destination 
+            new_msg.data['destination'] = _destination
 
         return new_msg
 
@@ -147,7 +147,7 @@ def _move_files(self, message):
             if return_message is not None:
                 break
             return_message = self._move_file(pathname, message, rel_path)
-            if return_message.type is "err":
+            if return_message.type == "err":
                 break
 
         return return_message
@@ -931,7 +931,7 @@ def unpack(pathname,
            compression=None,
            working_directory=None,
            prog=None,
-           delete="False",
+           delete=False,
            **kwargs):
     """Unpack *pathname*."""
     del kwargs
@@ -945,7 +945,7 @@ def unpack(pathname,
         except Exception:
             LOGGER.exception("Could not decompress %s", pathname)
         else:
-            if delete.lower() in ["1", "yes", "true", "on"]:
+            if delete:
                 os.remove(pathname)
             return new_path
     return pathname
diff --git a/trollmoves/tests/test_server.py b/trollmoves/tests/test_server.py
index fc3090d9..e41a12af 100644
--- a/trollmoves/tests/test_server.py
+++ b/trollmoves/tests/test_server.py
@@ -300,3 +300,17 @@ def test_requestmanager_is_delete_set_True(patch_validate_file_pattern):
     port = 9876
     req_man = RequestManager(port, attrs={'delete': True})
     assert req_man._is_delete_set() is True
+
+
+def test_unpack_with_delete(tmp_path):
+    """Test unpacking with deletion."""
+    import bz2
+    zipped_file = tmp_path / "my_file.txt.bz2"
+    with open(zipped_file, 'wb') as fd_:
+        fd_.write(bz2.compress(b"hello world", 5))
+
+    from trollmoves.server import unpack
+
+    res = unpack(zipped_file, delete=True, working_directory=tmp_path, compression="bzip")
+    assert not os.path.exists(zipped_file)
+    assert res == os.path.splitext(zipped_file)[0]