diff --git a/win2xcur/main/win2xcur.py b/win2xcur/main/win2xcur.py
index e50b644..b13958b 100644
--- a/win2xcur/main/win2xcur.py
+++ b/win2xcur/main/win2xcur.py
@@ -9,8 +9,7 @@ from typing import BinaryIO
 
 from win2xcur import shadow
 from win2xcur.parser import open_blob
-from win2xcur.writer import to_x11
-from win2xcur.writer.x11 import check_xcursorgen
+from win2xcur.writer.x11 import check_xcursorgen, to_x11
 
 
 def main() -> None:
diff --git a/win2xcur/parser/xcursor.py b/win2xcur/parser/xcursor.py
index a6bc5af..6339c89 100644
--- a/win2xcur/parser/xcursor.py
+++ b/win2xcur/parser/xcursor.py
@@ -1,6 +1,6 @@
 import struct
 from collections import defaultdict
-from typing import Any, Dict, Iterator, List, Tuple, cast
+from typing import Any, Dict, List, Tuple, cast
 
 from win2xcur.cursor import CursorFrame, CursorImage
 from win2xcur.parser.base import BaseParser
diff --git a/win2xcur/writer/windows.py b/win2xcur/writer/windows.py
index bfd1a73..5bf325f 100644
--- a/win2xcur/writer/windows.py
+++ b/win2xcur/writer/windows.py
@@ -3,7 +3,8 @@ from itertools import chain
 from typing import List, Tuple
 
 from win2xcur.cursor import CursorFrame
-from win2xcur.parser import ANIParser, CURParser
+from win2xcur.parser.ani import ANIParser
+from win2xcur.parser.cur import CURParser
 
 
 def to_cur(frame: CursorFrame) -> bytes:
@@ -59,7 +60,8 @@ def to_ani(frames: List[CursorFrame]) -> bytes:
         cur_list,
     ]
     body = b''.join(chunks)
-    return ANIParser.RIFF_HEADER.pack(ANIParser.SIGNATURE, len(body) + 4, ANIParser.ANI_TYPE) + body
+    riff_header: bytes = ANIParser.RIFF_HEADER.pack(ANIParser.SIGNATURE, len(body) + 4, ANIParser.ANI_TYPE)
+    return riff_header + body
 
 
 def to_smart(frames: List[CursorFrame]) -> Tuple[str, bytes]: