diff --git a/gnes/preprocessor/helper.py b/gnes/preprocessor/helper.py
index 672fe3a2..09e93580 100644
--- a/gnes/preprocessor/helper.py
+++ b/gnes/preprocessor/helper.py
@@ -135,7 +135,7 @@ def split_video_frames(buffer_data: bytes,
     return [np.array(Image.open(io.BytesIO(chunk))) for chunk in chunks]
 
 
-def get_gif(images, fps=4):
+def get_gif(images: 'np.ndarray', fps=10):
     cmd = ['ffmpeg', '-y',
            '-f', 'rawvideo',
            '-vcodec', 'rawvideo',
diff --git a/gnes/preprocessor/io_utils/__init__.py b/gnes/preprocessor/io_utils/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/gnes/preprocessor/io_utils/gif.py b/gnes/preprocessor/io_utils/gif.py
index 6cb34a32..b841cc9a 100644
--- a/gnes/preprocessor/io_utils/gif.py
+++ b/gnes/preprocessor/io_utils/gif.py
@@ -47,7 +47,7 @@ def decode_gif(data: bytes, fps: int = -1,
 
 
 def encode_gif(
-        images: List[np.ndarray],
+        images: np.ndarray,
         scale: str,
         fps: int,
         pix_fmt: str = 'rgb24'):