diff --git a/src/libtorio/ffmpeg/stream_reader/stream_reader.h b/src/libtorio/ffmpeg/stream_reader/stream_reader.h
index 5550d10777..a8e1d9f065 100644
--- a/src/libtorio/ffmpeg/stream_reader/stream_reader.h
+++ b/src/libtorio/ffmpeg/stream_reader/stream_reader.h
@@ -66,8 +66,8 @@ class StreamingMediaDecoder {
   /// (opening source).
   explicit StreamingMediaDecoder(
       AVIOContext* io_ctx,
-      const std::optional<std::string>& format = c10::nullopt,
-      const std::optional<OptionDict>& option = c10::nullopt);
+      const std::optional<std::string>& format = std::nullopt,
+      const std::optional<OptionDict>& option = std::nullopt);
 
   /// @endcond
 
@@ -81,8 +81,8 @@ class StreamingMediaDecoder {
   /// (opening source).
   explicit StreamingMediaDecoder(
       const std::string& src,
-      const std::optional<std::string>& format = c10::nullopt,
-      const std::optional<OptionDict>& option = c10::nullopt);
+      const std::optional<std::string>& format = std::nullopt,
+      const std::optional<OptionDict>& option = std::nullopt);
 
   ///@}
 
@@ -205,9 +205,9 @@ class StreamingMediaDecoder {
       int64_t i,
       int64_t frames_per_chunk,
       int64_t num_chunks,
-      const std::optional<std::string>& filter_desc = c10::nullopt,
-      const std::optional<std::string>& decoder = c10::nullopt,
-      const std::optional<OptionDict>& decoder_option = c10::nullopt);
+      const std::optional<std::string>& filter_desc = std::nullopt,
+      const std::optional<std::string>& decoder = std::nullopt,
+      const std::optional<OptionDict>& decoder_option = std::nullopt);
   /// Define an output video stream.
   ///
   /// @param i,frames_per_chunk,num_chunks,filter_desc,decoder,decoder_option
@@ -226,10 +226,10 @@ class StreamingMediaDecoder {
       int64_t i,
       int64_t frames_per_chunk,
       int64_t num_chunks,
-      const std::optional<std::string>& filter_desc = c10::nullopt,
-      const std::optional<std::string>& decoder = c10::nullopt,
-      const std::optional<OptionDict>& decoder_option = c10::nullopt,
-      const std::optional<std::string>& hw_accel = c10::nullopt);
+      const std::optional<std::string>& filter_desc = std::nullopt,
+      const std::optional<std::string>& decoder = std::nullopt,
+      const std::optional<OptionDict>& decoder_option = std::nullopt,
+      const std::optional<std::string>& hw_accel = std::nullopt);
 
   /// @cond
   /// Add a output packet stream.
@@ -315,7 +315,7 @@ class StreamingMediaDecoder {
   /// @param timeout See `process_packet_block()`
   /// @param backoff See `process_packet_block()`
   int fill_buffer(
-      const std::optional<double>& timeout = c10::nullopt,
+      const std::optional<double>& timeout = std::nullopt,
       const double backoff = 10.);
 
   ///@}
@@ -383,7 +383,7 @@ class StreamingMediaDecoderCustomIO : private detail::CustomInput,
       int buffer_size,
       int (*read_packet)(void* opaque, uint8_t* buf, int buf_size),
       int64_t (*seek)(void* opaque, int64_t offset, int whence) = nullptr,
-      const std::optional<OptionDict>& option = c10::nullopt);
+      const std::optional<OptionDict>& option = std::nullopt);
 };
 
 // For BC
diff --git a/src/libtorio/ffmpeg/stream_writer/stream_writer.h b/src/libtorio/ffmpeg/stream_writer/stream_writer.h
index fc8b3ae621..a646d3f38a 100644
--- a/src/libtorio/ffmpeg/stream_writer/stream_writer.h
+++ b/src/libtorio/ffmpeg/stream_writer/stream_writer.h
@@ -38,7 +38,7 @@ class StreamingMediaEncoder {
   /// @param format Specify output format.
   explicit StreamingMediaEncoder(
       AVIOContext* io_ctx,
-      const std::optional<std::string>& format = c10::nullopt);
+      const std::optional<std::string>& format = std::nullopt);
 
   /// @endcond
 
@@ -50,7 +50,7 @@ class StreamingMediaEncoder {
   /// ``dst``.
   explicit StreamingMediaEncoder(
       const std::string& dst,
-      const std::optional<std::string>& format = c10::nullopt);
+      const std::optional<std::string>& format = std::nullopt);
 
   // Non-copyable
   StreamingMediaEncoder(const StreamingMediaEncoder&) = delete;
@@ -113,13 +113,13 @@ class StreamingMediaEncoder {
       int sample_rate,
       int num_channels,
       const std::string& format,
-      const std::optional<std::string>& encoder = c10::nullopt,
-      const std::optional<OptionDict>& encoder_option = c10::nullopt,
-      const std::optional<std::string>& encoder_format = c10::nullopt,
-      const std::optional<int>& encoder_sample_rate = c10::nullopt,
-      const std::optional<int>& encoder_num_channels = c10::nullopt,
-      const std::optional<CodecConfig>& codec_config = c10::nullopt,
-      const std::optional<std::string>& filter_desc = c10::nullopt);
+      const std::optional<std::string>& encoder = std::nullopt,
+      const std::optional<OptionDict>& encoder_option = std::nullopt,
+      const std::optional<std::string>& encoder_format = std::nullopt,
+      const std::optional<int>& encoder_sample_rate = std::nullopt,
+      const std::optional<int>& encoder_num_channels = std::nullopt,
+      const std::optional<CodecConfig>& codec_config = std::nullopt,
+      const std::optional<std::string>& filter_desc = std::nullopt);
 
   /// Add an output video stream.
   ///
@@ -161,15 +161,15 @@ class StreamingMediaEncoder {
       int width,
       int height,
       const std::string& format,
-      const std::optional<std::string>& encoder = c10::nullopt,
-      const std::optional<OptionDict>& encoder_option = c10::nullopt,
-      const std::optional<std::string>& encoder_format = c10::nullopt,
-      const std::optional<double>& encoder_frame_rate = c10::nullopt,
-      const std::optional<int>& encoder_width = c10::nullopt,
-      const std::optional<int>& encoder_height = c10::nullopt,
-      const std::optional<std::string>& hw_accel = c10::nullopt,
-      const std::optional<CodecConfig>& codec_config = c10::nullopt,
-      const std::optional<std::string>& filter_desc = c10::nullopt);
+      const std::optional<std::string>& encoder = std::nullopt,
+      const std::optional<OptionDict>& encoder_option = std::nullopt,
+      const std::optional<std::string>& encoder_format = std::nullopt,
+      const std::optional<double>& encoder_frame_rate = std::nullopt,
+      const std::optional<int>& encoder_width = std::nullopt,
+      const std::optional<int>& encoder_height = std::nullopt,
+      const std::optional<std::string>& hw_accel = std::nullopt,
+      const std::optional<CodecConfig>& codec_config = std::nullopt,
+      const std::optional<std::string>& filter_desc = std::nullopt);
   /// @cond
   /// Add output audio frame stream.
   /// Allows for writing frames rather than tensors via `write_frame`.
@@ -179,13 +179,13 @@ class StreamingMediaEncoder {
       int sample_rate,
       int num_channels,
       const std::string& format,
-      const std::optional<std::string>& encoder = c10::nullopt,
-      const std::optional<OptionDict>& encoder_option = c10::nullopt,
-      const std::optional<std::string>& encoder_format = c10::nullopt,
-      const std::optional<int>& encoder_sample_rate = c10::nullopt,
-      const std::optional<int>& encoder_num_channels = c10::nullopt,
-      const std::optional<CodecConfig>& codec_config = c10::nullopt,
-      const std::optional<std::string>& filter_desc = c10::nullopt);
+      const std::optional<std::string>& encoder = std::nullopt,
+      const std::optional<OptionDict>& encoder_option = std::nullopt,
+      const std::optional<std::string>& encoder_format = std::nullopt,
+      const std::optional<int>& encoder_sample_rate = std::nullopt,
+      const std::optional<int>& encoder_num_channels = std::nullopt,
+      const std::optional<CodecConfig>& codec_config = std::nullopt,
+      const std::optional<std::string>& filter_desc = std::nullopt);
 
   /// Add output video frame stream.
   /// Allows for writing frames rather than tensors via `write_frame`.
@@ -196,15 +196,15 @@ class StreamingMediaEncoder {
       int width,
       int height,
       const std::string& format,
-      const std::optional<std::string>& encoder = c10::nullopt,
-      const std::optional<OptionDict>& encoder_option = c10::nullopt,
-      const std::optional<std::string>& encoder_format = c10::nullopt,
-      const std::optional<double>& encoder_frame_rate = c10::nullopt,
-      const std::optional<int>& encoder_width = c10::nullopt,
-      const std::optional<int>& encoder_height = c10::nullopt,
-      const std::optional<std::string>& hw_accel = c10::nullopt,
-      const std::optional<CodecConfig>& codec_config = c10::nullopt,
-      const std::optional<std::string>& filter_desc = c10::nullopt);
+      const std::optional<std::string>& encoder = std::nullopt,
+      const std::optional<OptionDict>& encoder_option = std::nullopt,
+      const std::optional<std::string>& encoder_format = std::nullopt,
+      const std::optional<double>& encoder_frame_rate = std::nullopt,
+      const std::optional<int>& encoder_width = std::nullopt,
+      const std::optional<int>& encoder_height = std::nullopt,
+      const std::optional<std::string>& hw_accel = std::nullopt,
+      const std::optional<CodecConfig>& codec_config = std::nullopt,
+      const std::optional<std::string>& filter_desc = std::nullopt);
 
   /// Add packet stream. Intended to be used in conjunction with
   /// ``StreamingMediaDecoder`` to perform packet passthrough.
@@ -226,7 +226,7 @@ class StreamingMediaEncoder {
   /// Open the output file / device and write the header.
   ///
   /// @param opt Private options for protocol, device and muxer.
-  void open(const std::optional<OptionDict>& opt = c10::nullopt);
+  void open(const std::optional<OptionDict>& opt = std::nullopt);
   /// Close the output file / device and finalize metadata.
   void close();
 
@@ -248,7 +248,7 @@ class StreamingMediaEncoder {
   void write_audio_chunk(
       int i,
       const torch::Tensor& frames,
-      const std::optional<double>& pts = c10::nullopt);
+      const std::optional<double>& pts = std::nullopt);
   /// Write video data
   /// @param i Stream index.
   /// @param frames Video/image tensor. Shape: ``(time, channel, height,
@@ -269,7 +269,7 @@ class StreamingMediaEncoder {
   void write_video_chunk(
       int i,
       const torch::Tensor& frames,
-      const std::optional<double>& pts = c10::nullopt);
+      const std::optional<double>& pts = std::nullopt);
   /// @cond
   /// Write frame to stream.
   /// @param i Stream index.